Category Archives: Radios

Dan’s respect for Hammarlund and the SP-600 series

Many thanks to SWLing Post contributor, DanH, who shares the following comment in response to this news article from the Citizen Times featured in Radio Waves yesterday:

Here are my thanks to members of the Amateur Radio community and The News-Record & Sentinel for remembering the legacy of Hammarlund Manufacturing Company Incorporated. It is good to know that this part of our radio history is valued and preserved. I loved the newspaper article!

I have a few vintage Hammarlund radios including two Super-Pro models. The SP-600-JX-21 is one of my daily drivers. This relatively late production SP-600 is in stock condition with the exception of a half dozen electrolytic capacitors that I replaced mostly in the power supply. By the time this SP-600 was built in 1957 Hammarlund had replaced the short-lived black beauty electrolytes with ceramic disc capacitors. Like military and industrial users I upgraded the original nickel plated tube shields with IERC heat dissipating tube shields where possible. I also installed vintage GE No. 1847 long-life incandescent bulbs as direct replacements for the brighter (too bright, for me) No. 47 dial lamps.

Here are my two most recent reception videos of the SP-600. The first features reception of Radio National da Amazonia and the second is a brief operating demo of the SP-600. The loudspeaker used in both videos is a full-range vintage Jensen 10? with matching transformer from the 1950’s instead of a communications range speaker typically used with these radios. This makes a big difference when listening to broadcasts.

This old Hammarlund is still working pretty well.

RN da Amazonia

SP-600 operating demo

Wow! Thank you for sharing this, Dan!

I used to own an SP-600 myself and I do miss it. The only reason I sold it is I was struggling to find a spot in my very compact shack where I could keep it on the air as a daily driver, yet still have enough room to bring new radios and accessories into the shack for evaluation. Moving it around all of the time (especially higher on my radio shelves) was incredibly difficult as she’s a hefty girl indeed! I ended up selling the ‘600 to a good friend for a song. That’s okay because like you, I know he’ll keep her in prime operating condition and I can even pop by to visit when I wish! I do miss having the ‘600 in the shack, though. It was truly a champion MW receiver as well!

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Hammarlund HR-10: David seeking advice about weather frequency adjustment

Many thanks to SWLing Post contributor, David Korchin, who needs a little advice regarding his recently restored Hammarlund HR-10:

After doing a heart transplant on my Hammarlund HR-10 Weather Sentry multi band receiver (I found a rough user on eBay and swapped out the chassis into my unspoiled case) the rig is running to spec; MW is very strong with that long bar antenna, the FM+AFC is terrific , and I’ve been sandbagging 75-80 m hams in their AM QSO’s. But the Weather band is fixed reception at 162.550 MHz—that works in New York City but the NOOA stations out here in easternmost Suffolk County NY use different frequencies. I’m wondering if the radio can be adjusted to another frequency? Or the crystal swapped?

Any ideas would be appreciated!

Please comment if you can help David sort out how he might add or modify the HR-10’s weather frequency!

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A comprehensive review of the Mission RGO One general coverage 50 watt transceiver

The following review was first published in the November 2020 issue of The Spectrum Monitor magazine:


A review of the Mission RGO One ham radio transceiver

by Thomas (K4SWL / M0CYI)

Wow…I love this!

If I am perfectly frank, that would sum up my initial impression of the Mission RGO One.

It was the 2018 Hamvention in Dayton, Ohio, and I had just met up with radio engineer Boris Sapundzhiev (LZ2JR) who was debuting the prototype of his 50-watt transceiver kit, the Mission RGO One. With its clean, functional design and simple front face, large weighted encoder, and enough tactile buttons and multi-function knobs to keep one’s most needed features within reach, the kit was certainly pushing all the right buttons for me.  Without a doubt, I was impressed from the start.

Boris (LZ2JR) the designer and engineer of the Mission RGO One.

To my mind, the RGO One smacks of classic 1990s-era transceivers:  a traditional tabletop front-facing panel, a large fold-out bail, and a unfussy backlit LCD display that’s large enough to read in the field and viewable at any angle.

Perhaps it’s only because I can’t turn off the innate radio reviewer, that I was rapidly checking mental boxes in this first encounter with the RGO One.  Indeed, when I first set eyes on any new radio, I do skim through my mental “operations checklist” to see how difficult the rig might be to use at home and/or in the field. Specifically, I’m looking for the following controls:

  • Encoder
  • AF Gain
  • RF Gain
  • Mode switch
  • Power output adjustment
  • Tune/Xmit button
  • Preamp/Attenuator
  • VFO A/B
  • Split and A=B
  • Mic gain and keyer speed
  • RIT
  • Filters
  • Band switching and direct frequency entry
  • Key and encoder lock

Of course, these days it’s fairly rare that radios actually contain all of these functions without the user having to dig into layers of menus, multi-function controls, or touch-screen options to access them.

Remarkably enough, the Mission RGO One, despite simple design, manages to include all of these features on the front panel without the need of embedded menus. In contrast with some of the radios I’ve tested and evaluated over the past several years, I could tell by the layout alone that the Mission RGO One was developed by an active ham radio operator and DXer: the controls are that intuitive.

Alas, the tantalizing prototype on Boris’ table in the 2018 Hamvention flea market was for show only.

Boris promised that he’d have fully-functional models available at the 2019 Hamvention. Because of this, following that first meeting in 2018, I kept in touch with Boris; we arranged to meet again at the 2019 Hamvention so I could take a second, much closer look at the RGO One––especially since he intended to start shipping the first very limited, early-production-run rigs shortly afterward.

So…did Boris deliver?  And more importantly: did the RGO deliver––?  Let’s find out.

On The Air

Within hours of taking delivery of the prototype radio, I had it in the field activating parks.

It was May 2019 when Boris delivered on his promise, handing me a loaner prototype RGO One. He did so with the understanding that the prototype was still a little rough around the edges. I acknowledged this, thinking in terms of a late Beta-test model since he welcomed reports of any bugs or anomalies I encountered and was fully prepared to address them.

After taking the initial RGO One to the field, I did note a few bugs, but nothing major.  All of my field notes were then sent to Boris and turned into action items.

Then, in July of 2020, Boris sent me a fully-upgraded Mission RGO One with the new internal ATU and optional adjustable filter. This radio represented the “fully-grown” production model, and in preparation to put it through its paces, I returned the prototype.

Although there are planned hardware upgrade options and, of course, firmware upgrades, the RGO One has now reached full maturity as a transceiver.

However, it was one thing to have ham-friendly ergonomic controls. The real question was, how did the RGO One stack up against the competition? It was time to find out.  After all, this is the danger of a “love at first sight” radio encounter––it often leaves the door open for disappointment, and of this I was well aware.

What follows is my full review of this 2020 Mission RGO One transceiver. Let’s take a deep dive into this rig…

Features and specifications

 

What follows are some of the RGO One features and highlights as written in the product manual (PDF):

  • QRP/QRO output 5 – 50W [can actually be lowered to 0 watts out in 1 watt increments]
  • All-mode shortwave operation – coverage of all HAM HF bands (160m/60m optional)
  • High dynamic range receiver design, including high IP3 monolithic linear amplifiers in the front end, and diode ring RX mixer or H-mode first mixer (option)
  • Low-phase noise first LO – SI570 XO/VCXO chip
  • Full/semi (delay) QSK on CW; PTT/VOX operation on SSB. Strict RX/TX sequencing scheme with no “click” sounds
  • Down conversion superhet topology with popular 9MHz IF
  • Custom-made crystal filters for SSB and CW and variable crystal 4 pole filter – Johnson type 200…2000Hz
  • Fast-acting AGC (fast and slow) with 134kHz dedicated IF
  • Compact and lightweight body, only 5 lbs
  • Custom-made multicolor backlit FSTN LCD
  • Custom-molded front panel with ergonomic controls
  • Silent operation with no clicking relays inside – solid state GaAs PHEMT SPDT switches on RX (BPF and TX to RX switching) and ultrafast rectifying diodes (LPF)
  • Modular construction – Main board serves as a “chassis” also fits all the external connectors, daughter boards, plus inter-connections, and acts as a cable harness
  • Optional modules – Noise Blanker (NB), Audio Filter (AF), ATU, XVRTER, PC control via CAT protocol; USB UART – FTDI chipset
  • Double CPU circuitry control for front panel and main board – both field programmable via USB interface
  • Memory morse code keyer (Curtis A, CMOS B); 4 Memory locations 128 bytes each

Build quality

First impressions proved accurate in terms of construction.  I’m very pleased with the build quality of the Mission RGO One. Keep in mind, however, you might note from the photos that some items––like the volume and multifunction knobs––are 3D printed, and I’m not certain if they’ll ever have custom knobs manufactured.  But I really don’t even think this is necessary, as the 3D printed ones are very nice, indeed––moreover, should a replacement ever be needed, I love the idea I could simply print one myself!

The RGO One main optical encoder/tuning knob is just brilliant. It’s weighted properly for the right amount of “heft” while tuning. I’m very pleased with the overall feeling and quality. It’s substantial, yet silky-smooth in operation, just what I look for in a tuning knob.

On the back of the unit, there is an externally-mounted heat sink with two small fans. These fans are quiet and efficient.

The chassis and bail are both top-shelf quality and should withstand years of field use. Just do keep in mind that like almost every other amateur transceiver currently on the market (save the recently reviewed lab599 Discovery TX-500), the chassis is neither water-proof nor weather-proof, so will require common-sense care to protect it from the elements.

Portability

The Mission RGO is relatively compact, lightweight (only 5 lbs without the ATU), and has a power output of up to 55 watts, even though the specs list just 50 watts. As a point of comparison, most other rigs in this class have a maximum output of 10 to 20 watts, and require an external amplifier for anything higher. The form factor is very similar to the Elecraft K2.

The light weight of the rig and the extra power makes the RGO One a capable and versatile field radio. Although the RGO One is configured like a desktop radio (with a front-facing panel), it’s still relatively compact and can easily be set up on a portable table, chair, or on the ground. Unlike field-portable rigs with top-mounted controls (think the Elecraft KX3 or KX2), obviously, it would be tough to do handheld or laptop operation.

The RGO One should also play for a long time on battery power as the receive current drain is a respectable 0.65A with the receiver preamp on. It’s not as efficient as, say, an Elecraft KX3 or the new Icom IC-705, but keep in mind the RGO One can provide 50 watts of output power and has a proper, internally-mounted, amplified speaker. The popular 100 watt Yaesu FT-891, in comparison, has a current drain closer to 1.75 to 2.0 amps [update: actually the specifications indicate 2 Amps in receive, but user reports are less than half that amount].  I pair the RGO One with my larger 15 aH Bioenno LiFePo battery. When fully-charged, I can operate actively for hours upon hours without needing to recharge.

Mission RGO One Bioenno LiFePo

The Bioenno 15aH battery powers the Mission RGO One for hours at a time in the field.

If it’s any indication of how much I wanted to take this rig to the field, when Boris handed me the prototype RGO One on Saturday at the 2019 Hamvention, I had it on the air that same day doing a Parks On The Air activation at an Ohio State Park.

Since then, I’ve easily taken the Mission RGO One on 30 or more park activations.

Performance

What’s most striking and obvious about the Mission RGO One’s receiver from the moment you turn it on is the low noise floor. It’s incredibly quiet. So much so that more than once, I’ve double checked to make sure RF gain hadn’t been accidentally altered as I started a field activation. I’d call CQ a few times, though, and when stations return they literally pop out of the ether. The RGO One currently has no digital noise reduction (DNR) but frankly, I don’t miss it like I might in other transceivers. Indeed, the RGO One is a radio I’ve reached for when the bands are noisy because the AGC and receiver seem to handle rough atmospheric conditions very well.

The RGO One’s built-in, top-mounted speaker provides ample audio levels for the shack, but in a noisy field environment, I wish it had a little more amplification. I’ve also used my Heil Pro headset and even inexpensive in-ear earphones connected to the front panel headphones jack in the field. The audio via headphones is excellent.

Let’s take a look at how well the RGO One performs by mode:

CW

First and foremost, CW operators will appreciate the RGO One’s silky-smooth full break-in QSK. The  RGO One employs clickless and quiet pin diode switching–a design feature I’ve become particularly fond of as traditional T/R relays can be noisy and distracting when not using headphones.

The RGO One also has a full compliment of adjustments for the CW operator including adjustable delay (default is 100ms), iambic mode, weight ratio, hand key/paddle, adjustable pitch, and sidetone volume.

The key jack is a standard three conductor 1/8” jack found on most modern transceivers. It’s located on the back of the radio.

My review unit has the optional variable width narrow filter which I highly recommend if operating in crowded conditions. I’ve used the RGO One on ARRL Field Day and found that it easily coped with crowded band conditions. Even after a few hours on the air, I had very little listener fatigue.

I also find that, as I mentioned earlier, CW signals just seem to “pop” out of the ether due to the low noise floor and excellent sensitivity/selectivity.

The RGO one also sports four CW keying memories where you can record your CQ, callsign, or even contest exchange. I’ve become incredibly reliant on memory keying to help facilitate my workflow in the field—while the radio is automatically sending my CQ or my regards and callsign to an station I’ve just worked, my hands are free to log the contact, adjust the radio, or even eat lunch!

Memory keying does require one long-press of the “6” button followed by either the “1,” “2,” “3,” or “4” button to play a message. Occasionally I won’t hold the 6 button long enough and accidentally move my frequency down one meter band since the 6 button is also the band “down” button. While it doesn’t happen often, it’s frustrating when it does but I think it could easily be fixed in the firmware as it’s really a timing issue.

SSB

Likewise, phone operators will be very pleased with the Mission RGO One. During all of my testing, I’ve only used the microphone supplied with the radio mainly because I don’t currently own another radio with an RJ-45 type microphone connector.

I do love the fact the microphone port is on the front panel of the radio—it’s very easy to connect and disconnect (in contract to the recently released Icom IC-705, for example). I’ve gotten excellent audio reports with the RGO One in SSB mode and have even monitored my own tests and QSOs via the KiwiSDR network.

Compression, gain, and VOX controls are easily accessible. One missing feature at present is a voice memory keyer. For field operators activating sites for the POTA, WWFF, or SOTA program, voice memory keying is huge as it saves your voice from calling “CQ” over the course of a few hours. I understand Boris does plan to implement voice memory keying in a future speech processor board.

AM Mode

Since the RGO One has general coverage receive and since I’m a shortwave broadcast listener, I was disappointed to find that there is presently no AM mode. Boris told me he does plan to add AM mode, “to be implemented in future versions of the IF/AF board only on RX.”

With that said, I can always zero-beat a broadcaster and use a wide SSB filter to listen to broadcasts which is more than I could do, for example, with my (ham band only) Elecraft K2.

At the end of the day, the RGO One is a high-performance, purpose-built ham radio transceiver, so the current lack of AM mode isn’t a deal-breaker for me, but I would love a wide AM filter on this rig.

ATU

The 2020 review model I received has the internal automatic antenna tuner which I feel is a worthy upgrade/addition. In the field, I’ve paired the RGO One with my Chameleon CHA Emcomm III Portable random wire antenna which requires an ATU in order to find matches across the bands. The pairing has been a very successful one because the Emcomm III can handle up to 50 watts power output in CW and covers the entire HF band when emptying the RGO One ATU.

 

Even though it’s a minor thing, I also like the fact that the RGO One ATU operates so quietly, even though with the present firmware it takes longer than some of my other ATUs to find a match.

Power

One thing I’ve found very useful in the field and, no doubt others will as well is the power output. In many ways, the RGO feels like a larger QRP radio (think Ten-Tec Argonaut V or VI) but it’s actually able to pump out 55 watts (often five watts more than specified). In single sideband mode, this is a meaningful amount of power output compared to, say, 5 or 10 watts. When I activate a rare park, or an ATNO (All Time New One), I’ve been taking the RGO One more times than not in order to get the best signal possible and maximum amount of contacts. Running full power, the rig never feels warm—heat dissipation is superb—and the fans on the back of the heat sink are super quiet.

I actually feel like the 50 watts of output power gives the RGO One a market niche since it sports top-shelf performance as you might expect in the venerable Elecraft K2, for example, but  not being a 10 watt or 100 watt radio, rather something in between which saves a little weight and also the need for heftier heat dissipation.

Other unique features

The RGO One has some interesting features not found in similar radios.

For one, there are no less than ten color options for the custom backlit LCD display, along with adjustable contrast and backlighting intensity.

The RGO One team also documents how to access hidden admin menus for granular adjustments to transceiver parameters, but of course you’d want to adjust those with caution and note values prior to changing them. When you receive your RGO One, Boris includes a sheet with all default values to make stepping back much easier.

Hands-on philosophy

At the end of the day, the Mission RGO One is a kit that can eventually be purchased in kit form, or as a fully assembled transceiver. It’s modular: you can add and upgrade features as you wish. Some field operators, for example, may wish to omit the ATU to save a little extra weight or cost. I actually love this philosophy and I think it’s one that’s made Elecraft such a successful manufacturer.

The process of upgrading firmware is slightly more involved than you might find with, say, an Elecraft, Icom, or Yaesu product. It’s a two stage process where one upgrades both the front panel and the main board separately. I completed a firmware update only a few weeks prior to publication. It took me perhaps 15 minutes with my PC as I followed Boris’ step-by-step instructions (http://lz2jr.com/blog/index.php/rgo-one-firmware-update-procedure/).

There is also an active email discussion group for the Mission RGO One (https://groups.io/g/RGO-ONE/) where participants share experiences, modifications, and even any glitches or bugs that are discovered. This group is closely monitored by the RGO One team, so items are addressed very quickly. I highly recommend joining this discussion group if you see an RGO One in your future.

Also, I’ve gotten great customer support from Boris (LZ2JR) and have heard the same from group members. He’s very much open to critical customer feedback.

Summary

Mission RGO One POTA

Every radio has its pros and cons. When I begin a review of a radio, I take notes from the very beginning so that I don’t forget some of my initial impressions. Here is the list I formed over the time I’ve spent evaluating the 2020 production model Mission RGO One.

Pros:

  • Excellent sensitivity and selectivity
  • Very low noise floor
  • Excellent, clean audio (see con)
  • Silky-smooth QSK
  • Full compliment of CW and SSB features and adjustments
  • CW memory keyer
  • Superb ergonomics with no need to access embedded menus for common features
  • 50 watts output power with effective quiet heat dissipation
  • Lighter weight compared with comparable transceivers
  • Direct frequency entry
  • Standard Anderson Powerpole power port on rear panel

Cons:

  • No voice keyer memory (at time of posting, but is planned in upgrade)
  • No notch or auto notch filter (at time of posting, but is planned)
  • No 6 meter option
  • No AM mode (at time of posting, but is planned)
  • Firmware updates are a two stage process
  • Would like slightly more audio amplification while using internal speaker in noisy outdoor environments

Conclusion

If you can’t tell, I’m impressed with the Mission RGO One because it does exactly what it sets out to do.  The RGO One is designed for an operator who appreciates rock-solid performance with simple, intuitive ergonomics.

While teaching an amateur radio course to our homeschool cooperative high school students last year, I picked the RGO One as the best field radio for HF demonstrations.

I’ll never forget setting the (prototype) RGO One for the first time on a folding table outside the classroom under a large tree. I had the students erect both an end-fed resonant antenna and a simple 20 meter vertical. I picked the RGO one because all of the adjustments we had talked about in the classroom—AGC, Filters, A/B VFOs, Direct Frequency Entry, Pre Amp, Attenuation—are on the front panel and one button press away.

We hopped on the air with one of my students calling CQ single sideband on the 20 meter band.  Her very first contact was with a station in Slovenia—and she simply beamed with excitement. All of my female students that term passed their Technician exam by the end of the term.

The RGO One is a very inviting radio.

I’ve had the luxury of testing, evaluating, and working with everything from one of the first prototypes to the latest updated version of the RGO One. It’s rare that I’m able to evaluate a radio over such a long period of time.

Even with the very early, bare-bones prototype, I was impressed with this transceiver’s performance characteristics. I’m not the only one either. It’s almost become routine new discussion group members join prior to receiving their radio, then announces how blown away they are with its performance. Check out eHam reviews, too—at time of posting, it’s a solid five stars at time of posting.

The RGO One reminds me of simple, classic radios of the 1980s and 90s, but underneath, it’s packing state-of-the-art performance.

Is it perfect? No radio is perfect, but I must say that for what it offers, it really hits the sweet spot for this radio operator.  It’s a joy to use.

There are still features in the works that will either be implemented with future firmware updates, or with future boards. In terms of performance and appearance, it reminds me of the Ten-Tec Eagle and Elecraft K2—both benchmark rigs in my world. And like the Eagle and K2, the RGO One is happy in the field, at home, or even on a DXpedition. It’s a simple radio that beckons to be on the air.

If you’re interested in the Mission RGO One, check the following web page for the pre-order form and pricing list. The RGO One is produced in batches, so you’ll need to reserve your model.

Click here to view the Mission RGO One order page.

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Review Notes: Xiegu GSOC Firmware updated to version 1.1–still a number of issues

For those of you who have been asking about the new Xiegu GSOC controller, I just updated my unit with the latest firmware (version 1.1).

Firmware notes show that it addresses the following items:

Xiegu GSOC FW V1.1
1. Solved the CW sidetone delay problem
2. Solved the problem of unstable system and occasional crash
3. Added RTTY modem
4. Added CW decoder
5. Added SWR scanner
6. Added FFT/Waterfall level adjustment
7. Added FFT line/fill color mixer

The list above was copied directly from the version notes.

I’m currently evaluating the GSOC/G90 pair which were kindly sent to me on loan by Radioddity. I upgraded the GSOC firmware to v1.1 this weekend.

What follows are some of my evaluation notes an observations after performing the upgrade.

Updating firmware

Updating the GSOC firmware is a pretty straight-forward process.

First you must download the GSOC firmware package (about 330 MB!) which includes a disk image and application to flash the image to a MicroSD card.

Yes, you’ll need a dedicated MicroSD card to upgrade the GSOC firmware–meaning, you can’t simply use a MicroSD card with data on it you’d like to keep because the process of flashing the ISO file also includes a full format with multiple partitions.

You’ll also need an SD Card reader/writer if your Windows PC doesn’t include one.

The included firmware application/tool makes it quite easy to flash a disk image on the MicroSD card.

After the MicroSD card has been prepared, simply turn off the GSOC, insert the MicroSD card on the left side of the GSOC, turn it back on and the GSOC will automatically boot from the MicroSD card and install the new OS/firmware.

Once the upgrade has completed, the GSOC will turn itself off and you must remove the MicroSD card.

If you want to restore the MicroSD card to one partition, you’ll need to perform another format and shrink the volumes.

CW sidetone latency (still issues)

After performing the upgrade, I hopped on the air and tried to make a few CW contacts since I noted in the version notes that the CW sidetone latency had been addressed. So far, my evaluation has pretty much been on hold because I’m unable to use CW mode with any sense of sending accuracy.

Unfortunately, I’m still finding that there’s still a bit of sidetone latency or keyer timing interfering with my ability to correctly send words and letters.

To my ear, it sounds like there’s much less latency in the sidetone audio now (compared with v1.0 which was a little insane) but I still struggle sending characters that end in a string of dits or dashes. For example, when I try to send a “D” the radio will often produce a “B” by adding one extra dit. Or if I try to send a “W” it might produce a “J”. I know something is a little bit off because I botched up two CW contacts with POTA stations yesterday as I tried to send my own callsign correctly.  And “73” was even problematic.

I’m guessing that there may still be a bit of audio lag between the G90 body (where the CW key is plugged in) and the GSOC (where the sidetone audio comes out). At the end of the day, the keying information must be sent to the GSOC from the G90 transceiver body and I assume the processor on the G90 is causing a bit of audio latency. Hopefully, Xiegu can sort this out. It’s a serious issue for anyone who wants to operate CW with the GSOC.

If you own the GSOC and operate CW, I’d love your comments and feedback.

Other updates

I tried using the CW decoder yesterday via the “Modem” menu and had limited success decoding a CW rag chew.

My markup in red: You can see at the very end of this conversation, it decoded the call sign, but interpreted “TU” as “TEA”

The decoder seemed to adjust the WPM rate automatically at one point, but as you can see in the image above, almost every dit was interpreted as an “E” and every dash a “T”. I must assume I don’t have it configured properly, but I don’t have an operator’s manual for reference and instruction.  I’ve also tried RTTY decoding, but haven’t been successful so far–I’m pretty sure this is also because I haven’t configured it properly.

SWR Scanner

I tested the new SWR scanner and it seems to work quite well, plotting SWR across a given frequency range. I did note, however, that it doesn’t seem to confine itself to the ham bands at all. It does inject a signal as it scans (I read 1.5 to 2 watts on my CN-801 meter).

I discovered out-of-band scanning when I took the photo above while trying to do a scan of the 30 meter band. It started around 9.6 MHz–well into the 31M broadcast band where it shouldn’t be transmitting. Xiegu needs to limit transmitted signal to the ham bands.

Memory Keying

I had hoped Voice Memory Keying would be added along with TX/RX recording. I do believe this will eventually be included in a future update. It appears via the “Modem” menu that CW Memory Keying has been added, but I can’t sort out how to make it work (again, a operation manual would be quite handy).

Audio recording

I had hoped transmit and received audio recording would be added in this firmware update; I understand this will eventually be added.

Combined current drain

As I mentioned in a previous GSOC update, the GSOC controller and G90 transceiver both need a 12V power source–indeed, each has a dedicated power port. The GSOC does not derive power from the G90.

I was originally told that the G90 and GSOC both pull about .60 amps in receive which would total 1.2 amps combined. My Hardened Power Systems QRP Ranger battery pack displays voltage and current; it’s not a lab-grade measurement device, but it’s pretty accurate. When I operate the GSOC and G90 at a moderate volume levels in receive, it appears to draw 0.95 to 0.97 amps–basically, 1 amp.

At home on a power supply, this is inconsequential, but in the field you’d need to keep this in mind when choosing a battery. It’s on par with a number of 100 watt transceivers.

Spectrum display images

I’m still finding images on the GSOC display that are not present in the received audio. I mentioned this in my initial overview and it doesn’t seem the firmware update addressed this.

I can only assume the spectrum imaging might be due to the I/Q input being too “hot” coming from the G90 via the shielded audio patchcord. Perhaps there’s a function to manually lower the I/Q gain, but I haven’t found that yet.

Spectrum images are most noticeable on the 31 meter band, but found them on the 20 meter ham band as well.

Here are two screen shots that show how images appear when a nearby signal overwhelms the GSOC:

Images are not present all of the time, only when a strong signal intrudes.

Ever-present noise and spurs in portions of spectrum

Perhaps this is related to the issue above, but there are some spurs on the spectrum display that seem to be present whether the G90/GSOC is hooked up to an antenna or dummy load.

Here’s a photo of the GSOC hooked up to an antenna:

And to a dummy load:

I’ve highlighted the spurs in red and as you can see, the intensity is stronger without an antenna thus I’m guessing this is internally-generated. The spurs do not move on the display as you change frequency.

Other notes

Again, I feel like the GSOC firmware isn’t mature and I can’t yet recommend purchasing it. I feel like Xiegu have rushed this unit to market.

I know that, over time, more features will be added and Xiegu certainly has a track record of following up.

When I evaluate a product, I keep a list of notes that I send to the manufacturer and to keep for my own reference. In Alpha and/or Beta testing, I’d share this info only with the manufacturer. Since the GSOC is a product that’s in production and widely available, however, I thought I’d share them here publicly:

  • GSOC volume control scale is 0 to 28. The difference between 0 (muted) to 1 seems to be the biggest increment. Volume 1 is actually a low to moderate volume level (i.e. a bit high).
  • Boot up time for the GSOC is 30 seconds
  • A keyboard and mouse or capacitive stylus are almost required for accurate operation. Many of the touch screen buttons are quite small and difficult to accurately engage with fingertip. The pointer seems to fall slightly below where fingertip makes contact on the screen.
  • Notch Filter seems to have no effect even after the v1.1 upgrade. There is no Auto Notch feature either.
  • I can’t seem to engage split operation even though there are A/B switchable VFOs and a “Split” button above the spectrum display. Using a keyboard and mouse doesn’t engage it either.
  • There are a number of announced features that I haven’t discovered including some WiFi and Bluetooth wireless functionality.
  • For field use, you must pack quite a bit of kit: the transceiver, the controller, CW key cable, microphone, serial cable, I/Q cable, G90 Power cable, and GSOC power cable. It would also be advisable to take a wireless keyboard and mouse especially if you plan to use any advanced functions like CW memory keying.
  • It doesn’t appear that you have CAT control of the GSOC which complicates digital operation. I believe many of us hoped the GSOC would make digital mode operation easier with the G90, but it hasn’t. Indeed, I assumed the GSOC would have an internal sound card for digi modes much like the Icom IC-7300 and IC-705. Use of VOX control is still  the best way to control transmit. I hope this can be upgraded else this would be a missed opportunity.
  • Since the v1.1 upgrade, the GSOC hasn’t crashed (it did frequently with the v1.0 firmware).
  • Not a pro or con, but I wish the AF Gain/Squelch was AF Gain/RF Gain like most HF transceivers. I’ve accidently engaged squelch twice which essentially muted audio. Pressing and holding the PO (Power Output) button opens the RG Gain control function).

The GSOC Universal Controller is an interesting accessory for the G90 and I’ve read comments from users that love the interface and added functionality.

If I’m being honest, I feel like I’m Beta testing the GSOC. I’ve yet to find a GSOC operation manual–this makes it very difficult to know if one has correctly configured the controller and engaged features/functions correctly. A quick start guide is included with the product, but it really only helps with connections and starting up the GSOC the first time. If you’re a GSOC early adopter, just be aware of this. Again, I’m pretty confident Xiegu will make refinements and include promised features in future firmware updates. I understand their software engineer closely monitors the GSOC discussion group as well. If you’re considering the purchase of a GSOC, I’d encourage you to join the GSOC group.

Questions? Comments?

As I said, I can’t recommend purchasing the GSOC controller yet. So much can change with firmware updates, however, I would encourage you to bookmark the tag GSOC to follow our updates here on the SWLing Post. I will update the GSOC controller each time a new firmware version is issued and until Radioddity asks for the loaner units to be returned. Again, many thanks to Radioddity for making this GSOC and G90 evaluation possible.

Feel free to comment with any questions you might have and I’ll do my best to answer them!

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Matt’s Monster Mediumwave Radio Selectivity Shootout!

Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), for sharing another brilliant audio comparison featuring benchmark portable radios:


Medium wave selectivity shootout

by Matt Blaze

I did another monster medium wave portable receiver comparison, this time with the aim of comparing receivers’ ability to deal with weak signals in the presence of strong adjacent channels.

Once again, I went up to the roof with eight MW portables with built-in antennas and recorded them simultaneously along with my “reference signal”, from an Icom R-9500 with an active loop on the roof. As before, I recorded a narrated stereo mix with the Icom on the left and the rotation of radios for a minute or two each on the right, but have “solo” tracks available for the full time for each radio. The nine receivers in the lineup this time included:

  • Icom R-9500 (with amplified Wellbrook loop antenna on roof)
  • Potomac Instruments FIM-41 Field Intensity Meter (my personal favorite)
  • Panasonic RF-2200
  • Sony IC-EX5MK2
  • C.Crane Radio 2E
  • Sangean PR-D4W
  • Sangean ATS-909X
  • Tecsun PL-990X
  • XHDATA D-808

I recorded two signals, one at night and one during the day.

Nighttime Signals

The first was at night: WWL New Orleans on 870 KHz. This signal is usually weak to medium strength here, but is a challenge for two reasons: first, it shares the frequency with Cuba’s Radio Reloj, and it is squeezed between two much higher strength signals: Toronto’s CJBC on 860, and NYC’s WCBS on 880. So you need a decent receiver and careful antenna orientation to receive it well here. That said, everything did pretty well, though you can see that some radios did better than others.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Daytime Signals

The second signal was during the day and was MUCH more marginal: WRJR Claremont, VA on 670 KHz. This was real challenge for any receiver and antenna. The signal was weak, and overshadowed by WCBM Baltimore on 680, a 50KW daytimer that is very strong here. (I’m not 100% sure that we were actually listening to WRJR – I never got an ID, but the station format and signal bearing was right). We can really hear some differences between the radios here.

The mix

Solo tracks

Icom IC-R9500

Potomac Instruments FIM-41 Field Intensity Meter

Panasonic RF-2200

Sony IC-EX5MK2

C.Crane Radio 2E

Sangean PR-D4W

Sangean ATS-909X

Tecsun PL-990X

XHDATA D-808

Everything (except the Icom) was powered by batteries and used the internal MW wave antenna, oriented for best reception by ear (not just maximizing signal strength, but also nulling any interference). The loop for the Icom was similarly oriented for best intelligibility.

For audio nerds: The recording setup involved a lot of gear, but made it fairly easy to manage capturing so many inputs at once. The portable radios were all connected to a Sound Devices 788T recorder, with levels controlled by a CL-9 linear mixing board control surface. This both recorded the solo tracks for the portables as well as providing a rotating mix signal for each receiver that was sent to the next recorder in the chain, a Sound Devices 833. The 833 received the mix audio from the 788T, which went directly to the right channel. The left channel on the 833 got audio from a Lectrosonics 822 digital wireless receiver, which had the feed from the Icom R-9500 in the shack (via a Lectrosonics DBu transmitter). The center channel on the 833 for narration of the mix, which I did with a Coles 4104B noise-canceling ribbon mic. This let me record fairly clean audio in spite of a fairly noisy environment with some wind.

All the radio tracks were recorded directly off the radios’ audio line outputs, or, if no line out was available, from the speaker/headphone jack through a “direct box” interface. I tried to make the levels as close to equal as I could, but varied band conditions and different receiver AGC characteristics made it difficult to be completely consistent.

Making the recordings was pretty easy once it was set up, but it did involve a turning a lot of knobs and moving faders in real time. I must have looked like some kind of mad scientist DJ to my neighbors, some of whom looked at me oddly from their own roofs.

Happy Thanksgiving weekend!


Thank you, Matt, for another brilliant audio comparison! I appreciate the attention and care you put into setting up and performing these comparisons–not an easy task to say the least. That Potomac Instruments FIM-41 is an impressive machine!

By the way, I consider it a badge of honor when the neighbors look at me as if I’m a mad scientist. I’m willing to bet this wasn’t your first time! 🙂

Post readers: If you like this audio comparison, please check out Matt’s previous posts as well:

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CQ Satellite: ARISS FM Repeater, Ham Sats, Tracking, Antennas, and Looking At The Future

Many thanks to SWLing Post contributor, Dan Van Hoy (VR2HF), who shares the following guest post:


ARISS FM Repeater May Be Back on Early December and a Short Ham Satellite Summary

by Dan Van Hoy (VR2HF)

I’ve recently had a lot of fun learning about the current batch of ham satellites and operating through some of them for the past several months with only a Diamond discone (and a short run of RG-213 double-shielded coax), Yaesu FT-817 (for SSB/CW) and TYT TH-9800 for FM satellites (more power, Scotty!). This simple set-up has yielded hours and hours of great fun. The last time I did satellite work was in the ’70s making contacts from my car through Oscar 6. If I had a car here in Hong Kong I might try it again!

Here’s my living room TV tray and sofa shortwave and satellite station (no XYL in house at the moment).

ARISS FM Repeater

One of the recent highlights for both newcomers to satellite operations and old-timers was working the International Space Station’s (ISS) new FM repeater which came on the air in early September. It is a specially modified Kenwood D710-GA VHF/UHF transceiver. Unfortunately, it was only operational for about a month. For the past several weeks it has been used mostly in APRS mode.

The ARISS FM repeater runs five watts and sounds just like a regular terrestrial repeater in many ways. You can work it with any dual-band VHF/UHF FM rig and the right antenna. Full-duplex is not required, but it helps. Lower power requires some kind of gain antenna, but receiving can be done with simple antennas.

The ARISS organization just updated the schedule for the ARISS operation with this announcement:

“Next mode change (cross band repeater) targeting early December.”

YEAH! What a nice Christmas present!

Here’s a link to the full ARISS information page:

https://www.ariss.org/current-status-of-iss-stations.html

ARISS QSO with E21EJC

Here’s a Youtube video of one of my ARISS contacts with E21EJC. It was right after he came back from his DXpedition hauling microwave gear and dishes out to the Thai countryside to work the QO-100 geosynchronous satellite. I tell him “welcome home and have a good rest.” Kob really is “Mr Satellite!” He has posted hundreds of Youtube videos of satellite contacts.

In addition, here is video of their HS0AJ/P special “portable” station antennas for QO-100. 10 GHz RX dish (downlink) and 2.4 GHz TX dish (the big one). I listened to Kob and his friend make several QSOs via the QO-100 WebSDR:

Amazing the things we hams do just to spray some RF in the right direction!

Beyond the ARISS: A Ham Satellite Summary

Presently, AO-91 is probably the most popular FM satellite, along with SO-50, AO-27 and PO-101. RS-44, a linear satellite for SSB and CW, is far and away the most popular for those modes. RS-44 is in a higher orbit providing less Doppler shift and longer contact times per pass. You can easily see from the Amsat status page which satellites are in operation and which are the most popular. Many of the ham satellites do not provide two-way communication capability, but still have beacons (CW and data) that can be heard (those are in YELLOW on the Amsat status page). Everyone with a ham callsign can contribute by by uploading a reception report of the satellites you hear or work.

Full-duplex on SSB/CW satellite work is very desirable but not mandatory. I have learned you can make contacts without it coupled with a little skill and some luck. Staying near the center of the satellite’s particular passband is helpful. Sadly, there are few full-duplex rigs available these days. One of the best may be the Yaesu FT-847 which can be found on the used market. Some satellite ops are using SDRs for RX and a ham rig for TX to achieve full-duplex. I’m going to try that soon using two Diamond discones and vertical separation.

For current status of all ham satellites and ARISS operation, go here:

https://www.amsat.org/status/index.php

Tracking

For tracking the ham sats and ISS, I like the Heavens-Above app (or Webpage: https://heavens-above.com/). The Pro version of Heavens Above is worth every penny. In the app, I put only the active satellites I am interested in in the search box. That way all the remaining unusable satellites will be ignored. Heavens-Above also lists the satellite operating frequencies for a quick reference.

 

One cool side note. With Heavens-Above, you can also see when ISS visible passes are available over your area (almost always near sunrise/sunset). Look for the passes with a magnitude greater than -3.0. If you have clear skies or a thin layer of clouds it’s quite a treat to see the ISS zoom overhead at 17, 000 miles per hour. When the ARISS repeater is operating, you can see and hear the ISS! The screen shot above is a visible pass at -3.9 magnitude, as bright as Venus.

Antennas

I have found my Diamond discone to work quite well for satellite operation. It’s probably the cheapest, simplest and most effective antenna you can use for this application If you really get interested in satellite work you can always spend the big bucks for AZ/EL rotators and beams as well as the software to run it all including tuning your rig to compensate for Doppler shift. Or you can buy quite expensive omni-directional antennas designed specifically for satellite use. So far, the KISS approach has worked well for me.

The Future Is Now

Finally, we can all get a taste of the future now by listening to the only ham radio geosynchronous satellite currently in operation, QO-100. It is centered on Europe and covers about 1/3 of the earth from Brazil to parts of Asia.

It was a thrill for me to listen (via the WebSDR listed below) to one of my new satellite colleagues, Mr Kob, E21EJC, who I call “Mr Satellite,” work Brazil and many other stations in the EU, the Middle-east and elsewhere through QO-100 during a special event operation from Thailand.

Anybody can listen to activity on QO-100 at the link below. When you get there just find the CLICK TO START SOUND! button. Then, click UNDER one of the signals in the waterfall and tune with the controls below. Weekends and holidays seem to be the best time to listen.

https://eshail.batc.org.uk/nb/

Because both the uplink and downlink frequencies are way up in the microwave bands, it’s not easy to get on QO-100, but, it appears to me, worth the effort. Maybe one day we will have two more QO-100-like birds linked together to cover the whole earth for 24/7 communication anywhere in the world. One can dream.

Full details about the QO-100 geosynchronous satellite can be found here:

https://amsat-uk.org/satellites/geo/eshail-2/

CQ Satellite!

When the propagation is bad, or actually anytime, ham satellites are a wonderful alternative to HF for having fun on the air.

Sorry, gotta go, RS-44 is just about here. CQ satellite, CQ satellite, de VR2HF…


Thank you so much for the satellite overview, Dan!

You’ve inspired me to get out of my comfort zone and try a little satellite work! The perfect project to do with my two daughters. I’m such a “below 30MHz” guy, I have to remind myself that there are actually some pretty amazing things you can do further up the band! When I purchase a discone antenna, I’m going to accuse you of being an enabler. Fair warning.

SWLing Post readers: Anyone else here tune to and track satellites? Please comment!

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Matt’s Marathon MediumWave Matchup

Many thanks to SWLing Post contributor, Matt Blaze (WB2SRI), who shares the following guest post:


Matt’s Marathon MediumWave Matchup

by Matt Blaze

Here’s another simultaneous receiver comparison, this time of ten portable medium wave receivers plus the Icom IC-R9500 (as a “reference receiver”). Previously, I used the same antenna for all the comparisons, but since these are portable receivers, I wanted to compare their performance using their built-in antennas. I did two comparisons, both of moderate to weak signals, one in the evening of a DX signal and the other in the daytime of a regional station.

The receivers were the Potomac Instruments FIM-41 (a “field intensity meter”), the Panasonic RF-2200, the Nordmende GlobeTraveler Exec (a beautiful German SW portable from 1968), the Sony ICF-EX5MK2, the CCrane Radio 2E, the Sangean ATS-909X, the Sangean D4W, the new Tecsun PL-990X, the XHDATA D-808, and finally the CountyComm GP5-SSB, plus the Icom IC-R9500.

All the receivers were recorded simultaneously. The radios (except the Icom R9500) were on the roof of my building and oriented for best reception (signal/noise) and kept sufficiently away from each other and other metal objects to avoid interference, The R9500 was in the shack and used a Wellbrook loop on the roof, also oriented for best signal/noise. I took the audio from the Line Out if one was available and from the headphone jack (via a “direct box” level converter) if not. I tried to match the audio levels reasonably closely, but different ACG characteristics made it difficult to be completely consistent across all the receivers throughout the sessions.

As in previous comparisons, for each session I’ve got a narrated stereo mix with the R9500 on the left channel and each receiver, for a minute or so one after the other on the right channel. You definitely want to use headphones to listen to these so you easily tell the left from the right radio. I’ve also provided mono “solo” recordings of each receiver for the full 15 minute-ish sessions so you can hear a receiver you’re interested in in detail.

Sound Devices 688 Multitrack Recorder

The recordings were made with a Sound Devices 688 recorder/mixer (which can record 12 simultaneous channels of audio). The portable radios were hardwired to the recorder, and the 9500 (which was downstairs) was connected via a Lectrosonics digital radio link. (Everything except the R9500 was on battery power to avoid mutual interference and ground loops, etc). The narration used a Coles noise canceling ribbon mic. Everything was done in a single take per session – there was NO postproduction editing – so I apologize for a few glitches and awkward moments.

You can see a “class photo” of the setup below, although the position and orientation of the radios was different during the actual recordings.

KCJJ

The first recording was at night, where we tuned to 1630 KCJJ in Iowa City, IA. This is effectively a 1KW clear channel; other than a few TIS stations, there’s not much else there on the east coast, and the signal is reliably weak to moderate but readable here on the east coast.

Narrated L/R stereo comparison:

Individual solo tracks:

CCrane Radio 2E

Sangean D4W

XHDATA D-808

Sony ICF-EX5MK2

Potomac Instruments FIM-41

CountyComm GP5-SSB

Nordmende GlobeTraveler Exec

Tecsun PL-990X

Icom IC-R9500

Panasonic RF-2200

Sangean ATS-909X


WSVA

The next recording was made during the day, of WSVA, a regional station in Harrisonburg, VA running 5KW in the daytime. Their signal is also reliably weak-moderate but readable here.

Narrated L/R stereo comparison:

Individual solo tracks (receiver should be obvious from the file name):

CCrane Radio 2E

Sangean D4W

XHDATA D-808

Sony ICF-EX5MK2

Potomac Instruments FIM-41

CountyComm GP5-SSB

Nordmende GlobeTraveler Exec

Tecsun PL-990X

Icom IC-R9500

Panasonic RF-2200

Sangean ATS-909X

Hope your readers find it useful!

-matt


An absolutely amazing job again, Matt! Thank you so much for taking the time to put this comparison together and sharing it here on the SWLing Post.  

Click here to check out all of Matt’s receiver audio comparisons.

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