Many thanks to SWLing Post contributor, Don (W7SSB), who shares the following photos of the new lab599 Discovery TX-500. Don notes that all of these photos were taken in Russia–where the TX-500 is manufactured–and include a number of Chameleon resonant field antennas.
Thanks for sharing these, Don. The thin form-factor of the TX-500, paired with a resonant antenna, certainly makes for a lightweight portable field setup!
Many thanks to SWLing Post contributor, Frank (ON6UU), who shares the following guest post which expands upon his previous DB4020 article:
by Frank Lagaet (ON6UU)
After telling you all about the DB4020 SSB build I’m here with the CW part of the kit, let’s say this is part 2. At a certain moment Javier let me know the CW interface kit was ready for shipment and some week later it was delivered to my QTH.
Again, a well packed kit arrived in a brown envelope, components and boards well packed in bubblewrap. I found even a board I did not expect which can hold a push button, a switch and the connector for your morse key. Javier thinks of everything it seems!
Unpacking the bubblewrap gave me this result, all components in 2 bags. In the bigger bag another 2 bags with 2 printboards, one for the CW interface, one for the CW filter. Great !! Checking the material bill resulted in all components there, another thumbs up.
I started, of course, immediately building it because I wanted CW in the transceiver as soon as possible. I don’t do much in SSB mode anymore and I already started missing CW on the DB4020, so I started my KX3 to listen to while I was populating the boards. I never thought CW was going to have this impact on me! …. ..
I started building the CW interface, again starting with all small items. I soon saw that the 2 relays which need to be soldered in were ideal to protect all components when the board is upside down, so I soldered them in very quickly. I then soldered in all other components ending with the elco’s.
Next phase was the CW filter. This board is small and came together in a blink of an eye, no problems there, the long legs of the 3 and 4 pin headers went in last.
The following day, I made all wire connections and soldered a 13pin connector, leaving one pin out since I want to have the option to choose the width of the CW signal I’m listening to. By cutting the FL CW + pin and adding an additional switch, I have now 500Hz or 2400Hz. Great option, for very little effort and simple. Another thumbs up here.
Now it was simply a matter of inserting the sub boards in the main board and all should be working. And it did! Hurray! The 500Hz filter works perfectly, filtering away all above or below stations nearby my operating frequency.
This is the result of the soldering work, 2 small boards which need to be inserted in the main board:
The CW interface still needs the 13pin header of which I cut one pin and mounted a switch to have the 2400Hz width.
The IC you see in the middle of the CW interface is the KB2 keyer which gives you several functions like 4 memories and beacon mode. The 4 potmeters are used to set the level on 40 and 20 meters, to set the delay between TX and RX switchover and to set side tone monitor level. The keyer also provides functions as keyer mode A or B, straight key function and can be set for speeds between 1 and 50WPM. WPM speed can be set in 2 different ways. Handy!
Here a picture of the CW filter inserted on the main DB4020 board.
The CW interface is inserted at the side of the main board, notice the 2 wires which go to the switch to allow switch-over between 500 and 2400Hz.
(Wiring still needs to be cleaned up in this picture.)
Finally, the result: a good working multimode QRP transceiver with 2 bands. It should be possible to make close to medium range with it as well as DX, even with QRP power.
And while I was building I also made a new key for this radio, it is made out of a relay and cost nearly nothing, looks good doesn’t it ? hihi.
The key, when in practiced hands (fingers hi), can do 50 WPM without a problem. My friend HA3HK does without blinking an eye at 40WPM with this kind of key and tells me that he can go faster if needed. Me? I’m going it a bit slower.
As this radio is only using little power (0.4A in RX, 1 to 2A in TX depending the power you set it) I thought, let’s make a battery pack for the radio.
The first plan was installing it in the box. I did not do that because the batterypack is also powerful enough to feed my KX2 and other QRP transceivers. Since I can use it with all of them, a loose battery works out better for me.
I started with an old laptop which had a broken screen and some other malfunctions, but still had a good battery, although I needed the battery connector of course. A piece of wood to mount the connector on was my next goal. And since I still have another laptop using the same batteries, I can charge the battery without problems. Simple, but good and it weighs much less than a gel cell battery.
The battery provides me with 12.5V and some 5Ah. Enough to last for hours on RX and for sure good enough to activate 2 SOTA sites in one day. It doesn’t look great but works great– that is what matters and to test it was more then good. Next will be getting the battery pack in a nice box. Better to re-use stuff than throwing it away I’m thinking.
I need to do something about the cover of the OLED display, there is still some work there to make it look nicer.
Some video can be seen on YouTube :
Finallym I’d like to thank you all for reading my articles about the DB4020. I had big fun soldering, tinkering with the box, making the key, and batteryholder/batterypack. My Hungarian friend HA3HK told me it looks a bit like a spy radio. …. ..
I also include one more time the link where you’ll find this kit :
https://www.qrphamradiokits.com/
73 TU ee
Frank
ON6UU
Thank you so much, Frank. No doubt, you had a lot of fun putting this excellent little kit together.
Implementing a filter switch was a fantastic idea and, obviously, not terribly difficult to do.
Based on the videos, the DB4020 has a low noise floor and very good receiver characteristics. I’m impressed that the CW portion of the radios has so many features as well, such as a memory keyer and beacon mode.
I also love how you reused that 5Ah laptop battery! I think that could almost give you a full day of SOTA activations at those consumption levels!
Thanks again for sharing this with us, Frank! We look forward to your future articles!
We posted an update about the new Tecsun PL-330 in late April 2020. While we didn’t have a lot of details, it’s worth reading.
We still don’t have a lot of details (as of today, July 3, 2020) but readers have been contacting me and commenting recently with links to online retailers who are already selling the PL-330.
SWLing Post contributor, Babis, shared a link to retailer (Taoboa.com, see above), this website with more information, and a review on this page.
To be clear: I am not placing an order for the Tecun PL-330 yet.
Indeed, as I mentioned in a previous post, my trusted Tecsun contact informed me that all of the new portables–the PL-990, H-501, and PL-330–are first being released as a “domestic” or pilot version in China. The pilot version is not the final and fully-updated/upgraded international/export version.
I will make an announcement here on the SWLing Post when the international/export versions are available for purchase.
To be clear, I can’t comment on the performance of the domestic models, but I do understand that the export models will likely have better specifications and even updated front panels/functions.
I also understand that the PL-990 will likely be the first export model in terms of availability.
Stay tuned! I’ll post any/all updates here on the Post.
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Many thanks to SWLing Post contributor, Gareth Buxton, who writes:
I “watch” the Anon-Co new additions page for changes and this morning I received an update that the PL-365 has been added. I think they only used to stock the non-usb Pl-360 version.
Click here to view the PL-365 page at Anon-Co.
Thanks for the tip, Gareth! The PL-365 is a very sensitive portable receiver and one of the least expensive with a proper SSB mode. I’m happy Anon-Co has added them to their inventory.
This past weekend my wife suggested that I do a Parks On The Air (POTA) activation. I think she wanted me out of the house so that she could prepare a birthday and Father’s day surprise with my daughters.
Of course, I happily obliged. My motto in French: “Profitez-en bien!” or “Make the most of it!”
Hazel (our dog) made it crystal clear she wanted to join me as well. She’s a great hiking companion and also watches out for black bears while I operate in the forest!
I decided to activate the DuPont State Game Land which was about a one hour drive from my house. Not only was it a new park for me, but it was also an ATNO (All-Time New One) for the POTA program.
I arrived onsite around 10:15 AM local and the parking lot for the forest trail heads was already packed.
It was a gorgeous day and this part of the DuPont Forest is well-known as a great mountain biking spot. I was very lucky to find a place to park.
We’re still in full social distancing mode in North Carolina due to Covid-19, so I had no desire to be anywhere near other people. Hazel and I went off-trail and hiked in about 1/4 of a mile to a nice clearing.
I set up the EFT Trail-Friendly end-fed antenna and operated with the Elecraft KX2.
I called for quite some time before I was spotted in the POTA system. After being spotted, I quickly racked up more than the required 10 contacts for the activation to be considered valid.
Although the weather was amazing and my antenna deployment was near-ideal, the bands were rough and unstable, so it was challenging.
Hazel and I packed up, moved out, and made a detour to visit a waterfall near a site I hope to activate in the near future. Here’s a short video:
Since Sunday, I’ve been visiting my hometown to help my parents with a few projects.
Yesterday, I had a four hour break in the day and decided to, of course, benefit from the beautiful weather and activate another new-to-me site. (Can you tell I’m addicted to POTA?)
I picked the Kerr Scott Game Land because it was “only” a 50 minute, rather scenic, drive.
It was quite easy finding a spot to park. Like most game lands, though, you must be prepared to go through off-road conditions. Part of the driveway into the site was incredibly muddy and definitely required at least all-wheel drive.
I set up my station in the shade and easily deployed the end-fed antenna once again.
This activation of Kerr Scott Game Land taught me an invaluable lesson: if you don’t have a “spot” of your activation on the POTA site, it’s like you don’t exist.
The POTA spotting network (much like popular DX spotting networks and clusters) is simply amazing. As a POTA hunter, you open the spots page and you’ll see a list of all of the current operators, their park numbers, and frequencies where last heard.
As an activator, your number one priority when you find an available frequency and start calling CQ is to be spotted on the POTA network.
If I have good mobile phone coverage at my site, I self-spot on the network. Within a few seconds of the spot posting, I’ll typically have a pile-up of a few operators trying to reach me.
If I have cell phone service, but no data, I’ll text my good friend Mike (K8RAT) and ask him to spot me on the network.
Kerr Scott, like most game lands, however, had no mobile phone service whatsoever, so I had no way to self-spot. In fact, this particular site was a good 15 minute drive from the nearest cell phone signal.
I called CQ for 30 to 40 minutes on my announced frequency, at the announced time, but not one single op come back to me.
Since I had just driven 50 minutes to reach this site, there was no way I was going to give up so easily. I had already set up my station in the trunk/boot of my car, so I simply secured it, disconnected the antenna and tied it to a tree branch (so it wouldn’t be in the way), and drove 15 minutes to a spot where I could send a quick message to Mike.
When I got back to the Kerr Scott, I hooked up the antenna, made one call, and had a pile-up of five operators I worked in rapid succession. In fact, I had my required 10 contacts within 8 minutes.
I do wonder how some of the most adventurous POTA activators manage to post spots while in remote areas. It’s such a key component of having a successful activation, I wonder if they use a satellite phone or satellite messaging device to text a friend for help. (If you’re a POTA or SOTA activator, I’d welcome your comments here!)
At any rate, I was very pleased to hammer out an activation so effortlessly once I was spotted on the network.
I should add here that CW activators have a secret weapon that’s incredible effective: the Reverse Beacon Network (RBN).
As a CW operator, the POTA spot system will read your callsign from the RBN as long as you have made an announcement on the POTA website in advance or have already been spotted to the POTA website. All you have to do is set up your station at the site and call CQ: the POTA system will auto-generate an accurate spot for you based on the frequency from the RBN. It’s incredibly effective and more than enough reason for me to think I should start doing CW activations.
I can operate CW–in fact, I routinely make CW contacts in POTA and in other contests. However, I’m not quite brave enough to call CQ from a POTA site and work my way through even a modest pile-up.
I need to practice CW more, and I will!
This week, I also take delivery of my Wolf River Coils TIA antenna. I’m looking forward to having the TIA as an option when I need a self-supporting antenna that’s quick to deploy and can handle up to 100 watts when needed.
Post readers: Did you play radio in the field this weekend? I’d love your comments–especially if you simply took a receiver outdoors to enjoy some noise-free broadcast listening!
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My Red Oxx Micro Manager packed with a full radio field kit
Yesterday, my family packed a picnic lunch and took a drive through Madison County, North Carolina. It was an impromptu trip. Weather was forecast to be pretty miserable that afternoon, but we took the risk because we all wanted to get out of the house for a bit.
Although that morning I had no intention of performing a Parks On The Air (POTA) activation, my family was supportive of fitting in a little radio-activity, so I jumped on the opportunity!
A quick glance at the POTA map and I determined that the Sandy Mush State Game Land (K-6949) was on our travel route. Better yet, the timing worked out to be ideal for a lunch picnic and before most of the rain would move into the area.
I had no time to prepare, but that didn’t matter because I always have a radio kit packed, fully-charged, and ready for the field.
My Red Oxx Micro Manager EDC pack (mine is an early version without pleated side pockets) holds an Elecraft KX2 field and antenna kit with room to spare (see photo at top of page).
The Micro Manager pack easily accommodates the entire kit
This 20 year old blue stuff sack is dedicated to antenna-hanging. It holds a reel of fishing line and a weight that I use to hang my end-fed antenna in a tree or on my Jackite telescoping fiberglass pole. The sack also accommodates a 10′ coax cable.
The Elecraft KX2 transceiver, EFT Trail-Friendly Antenna, hand mic, CW paddles, C.Crane earphones, and wide variety of connectors and cables all fit in this padded Lowe Pro pack:
The advantage to having a simple, organized radio kit at the ready is that everything inside has its own dedicated space, so there’s no digging or hunting for items when I’m ready to set up and get on the air.
This level of organization also makes it easy to visually inspect the kit–missing items stand out.
Yesterday I parked our car at one of the Sandy Mush Game Land parking areas, deployed my field antenna, and was on the air in a matter of seven minutes at the most.
Technically, this should read “Activator” parking area! (A questionable inside joke for POTA folks!)
We planned for heavy rain showers, so I fed the antenna line through the back of my car so that I could operate from the passenger seat up front.
I also brought my Heil Proset – K2 Boom Headset which not only produces better transmitted audio than the KX2 hand mic, but it frees up my hands to log stations with ease. This is especially important when operating in the front seat of a car!
The great thing about the KX2 is that it’s so compact, it can sit on my clipboard as I operate the radio (although typically I have an elastic strap securing it better). Since all of the KX2 controls are top-mounted, it makes operation a breeze even in winter weather while wearing gloves.
Since I routinely use the KX2 for shortwave radio broadcast listening as well, I know I always have a radio “locked and loaded” and ready to hit the air. My 40/20/10 meter band end-fed antenna works well for the broadcast bands, as long as there is no strong local radio interference (RFI). When I’m faced with noisy conditions, I pack a mag loop antenna as well.
Having a radio kit stocked and ready to go on a moment’s notice gives me a great sense of security, and not just for recreational ham and shortwave radio listening reasons.
Sometimes I travel in remote areas by car where I’m more than an hour away from the nearest town and where there is no mobile phone coverage.
If my car breaks down, I know I can always deploy my radio kit and get help from the ham radio community in a pinch. Herein lies the power of HF radio!
If you haven’t built a radio go-kit, I’d highly recommend doing so. Although I’m a bit of a pack geek, keep in mind that you don’t need to purchase special packs or bags for the job. Use what you already have first.
I’m plotting a detailed post about the anatomy of an HF radio field kit. In the meantime, I’m very curious how many of you in the SWLing Post community also have a radio kit at the ready–one based on a transceiver or receiver. Please comment!
Better yet, feel free to send me details and photos about your kit and I’ll share them here on the Post!
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After publishing a couple of posts about the Xiegu G90 QRP transceiver, I’ve gotten a number of inquiries from readers asking about the G90’s ability to receive AM broadcasts. Although I’ll address this in detail in my upcoming TSM review, I thought I’d also share a few notes with you.
One of the main reasons I decided to review the Xiegu G90 is I found so little information out there about how well the general coverage receiver worked for HF broadcast listening. The G90 has a frequency range of 0.5-30 MHz (SSB, CW, and AM), but I couldn’t find a specification showing the maximum width of the AM filter. I had seen a few display photos with the AM filter width indicated as 5.4 kHz–that’s not terribly wide, but workable.
Only moments after opening the box and putting the G90 on the air, I tuned to the Voice of Greece (9,420 kHz) and learned how to change the bandwidth. I was very pleased to find that in AM mode, the indicated filter width is actually half the actual width. This means, the G90’s AM filter can actually be widened to 10.8 kHz–brilliant!
In addition, the bandwidth adjustment is variable, meaning you’re not locked into pre-determined, stepped bandwidths as with so many other transceivers.
In this short video, I widen the AM filter while tuned to the Voice of Greece:
Here’s another video of the G90 tuned to Radio Exterior de España on 9,690 kHz. Although the REE transmitter is located across the Atlantic Ocean in Spain, they sound like a local here in North Carolina:
Overall, I’ve been very pleased with the G90 on the HF bands.
Of course, there’s no synchronous detector (although users have requested this in a future firmware version) and there’s no notch filter as of yet. While I expect Xiegu may consider adding a notch filter, I doubt they’ll ever add a sync detector as this rig is primarily aimed at QRP ham radio operation. Of course, I could be wrong.
I also haven’t found a way to completely disable the transmitter or set the power level to zero watts. It’s quite possible I simply haven’t discovered the appropriate setting for this yet. Disabling the transmitter adds an extra level of protection when I use receive-only amplified mag loop antennas, for example. Also, some G90 owners may purchase the rig for listening purposes only and would rather not accidentally key the transmitter or engage the ATU.
I purchased my Xiegu G90 from MFJ Enterprises because I wanted to support a US retailer. There are a number of other G90 distributors across the globe. Here’s a short selection:
I’m sure there are many other G90 retailers across the globe. Before placing an order, I would suggest you double-check availability as some retailers are on back-order.
Post Readers: Have you used the Xiegu G90 on the broadcast bands? Please comment with your thoughts!