Category Archives: Ham Radio

Understanding decibels

Many thanks to SWLing Post contributor, Marty, who shares the following article from Nuts and Volts magazine–a primer on decibels:

The “dee-bee” is everywhere in ham radio, and is used for characterizing everything from antenna performance to nano-sized signals. Learn the decibel (abbreviated as lower-case ‘d’ followed by an upper-case ‘B’ or ‘dB’) and you and your signal will go a long way!

From the ARRL Ham Radio License Manual’s online math tutorials for beginning hams (arrl.org/chpt-2-radio-signal-fundamentals), we introduce the decibel. “You have probably recognized deci as the metric prefix that means one-tenth. The unit we are really talking about here is the bel (a ratio of sound levels named for Alexander Graham Bell), so a decibel is just 1/10th of a bel. We use a decibel instead of a whole bel because the bel represents a rather large change in levels. The dB is a just-perceptible change and more useful as a unit of measurement.” As used in wireless, the decibel is the ratio of two power levels:

dB = 10 log10 (P2/P1)

Note that the dB has no units because it is a ratio. The dB is just a number that describes how much bigger or smaller one quantity is compared to the other. Both quantities themselves must have the same base units, though — watts, for example. If P2 is larger than P1, the dB value is positive, such as for amplifier gain. If P2 is less, the value is negative and represents attenuation or loss. (Somewhat confusingly, it’s common to specify an amount of attenuation as a positive value of dB. For example, “This filter attenuates the signal by 20 dB.”)

Click here to read the full article at Nuts and Volts.

Spread the radio love

Source files for Tom Lackamp’s NewLog logging application?

NewLog Entry Screen

I recently received an inquiry from SWLing Post contributor, Geroge (NJ3H), who is a big fan of the simple logging application NewLog.

NewLog was written by Tom Lackamp (formerly AB9B) who was very well regarded in the community. Several years ago, however, he seemed to disappear: his callsign was reassigned and his email no longer works. Many assume, of course, that he could be SK.

UPDATE: Many thanks to the SWLing Post readers who shared the sad news that Tom Lackamp passed away on 12/26/2017 at age 70.

George has attempted to track Tom down because there are a few minor modifications he’d like to make to NewLog.

I’m told Tom openly encouraged his users to modify NewLog’s source files that we believe to have been written in Delphi.

If you happen to have the source files for NewLog–or know of a way to locate them–can you please comment on this post? Perhaps NewLog can be given a second life in the hands of the right programmer. Of course, please comment if you know how to contact Tom Lackamp or if you know what might have happened to him.

Spread the radio love

Icom IC-705 price and availability

Note: We will update this post as pricing information is confirmed by retailers.

Many thanks to several SWLing Post readers who have been carefully tracking the price of the Icom IC-705 transceiver which is expected to start shipping around the second quarter of 2020.

Pricing in Japan: 124,800 yen

Paul Evans notes that the price in Japan, according to this Icom Japan press release [PDF], is 124,800 yen + tax. That’s roughly $1150-1200 USD.

Pricing in UK: £1200.

In addition, ML&S have recently posted updated details from Icom UK and have noted that they “anticipate a price of around £1200 (£1000.00 excluding VAT).” To put that in perspective, the IC-7300 is currently being offered for the same price and it’s been on the market a while now.

This could mean that after the IC-705 has been on the market for a while, discounts could place it well below that of the IC-7300. Of course, if history is an indicator, early adopters will likely pay the top price.

Pricing in US: [TBD]

No confirmation yet from US retailers, but at this point, I would bet we could see pricing around $999 USD. That would be a competitive starting point. Of course, once we have confirmation from retailers we’ll update this with actual figures.

Other regional pricing

We will update this post with pricing and availability once we confirm details. Please comment with any tips!


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love

TX Factor Episode 25

Many thanks to SWLing Post contributor, Eric (WD8RIF), who notes that the 25th episode of TX Factor was recently released. Here’s the show summary:

A post-election special – well, not really! Just a look at some more new and innovative AR products from this year’s Hamfest, including a potted history of the ever-popular and much revered range of transceivers and kits from Electraft with co-founder Eric Swartz WA6HHQ. There’s our free-to-enter draw with some excellent prizes from ML&S and RSGB to be won.

In this modern era of connectivity, we take the ever-present Internet for granted; it’s always there and continues to deliver our data from A to B without issue. But what would happen if that vital link failed? We visit Southampton and Portsmouth on the UK’s south coast to see how two city councils, assisted by a group of dedicated amateurs, plan to maintain their communications infrastructure via radio links alone, should the Internet go down.

Click here to view on YouTube or on the TX Factor website.

Spread the radio love

Just ordered the new $149/$199 uBITX v 6.0 QRP transceiver

Many thanks to SWLing Post contributor, Pete (WB9FLW), who notes that Ashhar Farhan (VU2ESE) has recently announced the availability of the uBITX v 6.0–as Pete notes, “just in time for the Holidays!

Pete shared the following message from Farhan:

Here is what [the uBITx v 6.0] looks like :

And of course, you can buy it on hfsignals.com. The shipping will happen from Tuesday onwards. We have a limited supply of the first 200 boards. The rest is for after Christmas.

The most important thing about this revision is that the Radio circuitry is almost unchanged. We have incorporated the connectors on the PCBs. So, this kit needs none of the confusing soldering. You snap in the TFT Raduino onto the main board, plug the power and antenna from the back, snap on headphones, plug in the mic (supplied with the kit) and off you go!

It is offered in two kits now : The basic kit (150 USD) is without the box (like old times) but with a microphone and two acrylic templates for the front and back panels.

The Full kit (199 USD) has the box with speaker, mounting hardware etc. Both are described on the website.

Now, about the TFT display:

For those who are using the 16×2 display and you would like to upgrade, you will have to do three things:

Add a heatsink to the 7805 of the raduino

Buy [here] and hook it up as per [this article].

Grab the new Arduino sketch from https://github.com/afarhan/ubitxv6

Background:

I have been hacking away at adding a TFT display for the Arduino for sometime. Finally, I managed to do this with a really inexpensive 2.8 inch TFT display that uses a controller called the ILI9341. The display update is slow but, clever guy that I am, the display very usable. it uses the same pins that earlier connected to the 16×2 LCD display. This display is available everywhere for a few dollars.

Many thanks, Pete, for sharing this announcement. The price was simply too attractive to me, so I just purchased the full kit for $199 US. (Thanks for being the good enabler you are, Pete!)

Update – 30 May 2020: Many thanks to Armin Sander who notes that the uBITX V6 full kit price has increased to $209 US.

I’ll post an update when I receive the transceiver and assemble it. I do hope this is a workable little radio–it would be pretty amazing for newcomers to the hobby to be able to get on the HF bands for a mere $200 US. I also love the fact that this is all based on open-source, hackable technologies.

Spread the radio love

Voice of Nigeria would like your reception reports

Photo source: 5N7Q

Many thanks to SWLing Post contributor, Harald Kuhl (DL1AX), who shares the following note posted on the 5N7Q DXpedition page:

UPDATE from Bodo, DF8DX.

5N7Q is QRT for now. Rene DL2JRM and Bodo DF8DX enjoyed this activity very much. We logged more than 20,000 QSOs in 9 days of operation. We were active from 10m to 160m in CW, SSB, RTTY and FT8.

While many friends appreciated getting some new band points, operating in FT8 and on the 60m band were first time ever activity.

Our QTH was in the broadcasting station of Voice Of Nigeria in Abuja. We were very grateful for this opportunity to use the broadcasting antennas that have 20dB gain into Europe, NA and SA. Asia was workable with our vertical dipoles or via long path. Unfortunately the giant rotatable antenna cannot be rotated at the moment but we hope that it is doable at the next activity. For low-bands we had some dipoles hanging from the 80m tall link tower. Our signal was good but we clearly had some RX trouble as the noise was very high. Complete log is uploaded to Clublog and Lotw as well. Please use OQRS to receive your paper QSL card via bureau or direct. There are still a lot of mails asking about QSOs that cant be found in the log. Please QRX, I will check all of them carefully but it takes some time. Our QSLs may be requested for free via bureau and Lotw is already uploaded, no waiting, no donation required for this service.

This activity would not have been possible without the effort and help by the staff from Voice Of Nigeria. All credit go to them. Please help us to help them. You may support future activities from here by keeping this wonderful transmitting station on air. Their current broadcasting schedule is: 0600-1100UTC on 7255kHz in AM (beaming to West Africa and SA) 1500-2100UTC on 11770kHz in AM (beaming to West Africa and NA) 1500-2100UTC on 15120kHz in DRM (beaming to EU). Please tune in and listen to Voice Of Nigeria.

Please send your listener reports to:

Head Of Engineering Engr. Jerimoth Canice Voice Of Nigeria Headquarter Oda Cres, Wuse 2 Abuja Nigeria [email protected]. Your listener reports are highly appreciated and help to keep transmitting from here.

Many thanks for sharing this, Harald! Readers, if you’ve logged VoN recently, please send them a reception report!

Spread the radio love

Mario acquires an Index Labs QRP++ general coverage transceiver

May 1996 QRP Plus ad from QST (Source: WD8RIF)

Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who shares the following guest post that was originally published on the Delaware Valley Radio Association (DVRA) website:


Amateur Radios from the Past: The Index Labs QRP++

The Index Labs QRP ++ was an intriguing little radio manufactured back in the mid-‘90’s by Index Labs of Gig Harbor, WA.  For those interested in QRP (low power operating, generally less than five watts output) this transceiver filled the bill perfectly.  It supports CW and SSB, transmits on all WARC bands, covers 1.8 – 30 MHz receive, has full break-in CW and a built-in iambic keyer.  It boasts 20 memories, weighs four pounds (perfect for portable operation) and measures 5.5 x 4 x 6 inches.  It’ll run on a 12V 1.5 amp supply or a stout 12 volt gel cell.  The internals (see second pic) are an engineering masterpiece with stacked circuit boards reminiscent of commercial rigs.

Index Labs QRP ++ on the test bench

I recently acquired one of these radios as I was heavily into QRP in the 1970’s while using a TenTec Argonaut 509 and vertical on our apartment house’s roof.  Back then the sunspot numbers scored much higher than today and many contacts were made, most notably a CW contact with Japan with a paltry one watt.  So for nostalgic reasons I had to have one of these QRP++ rigs even though more modern and sophisticated versions are available.

At the moment bench tested is being done prior to sending it into action.  One important component needing replacement was the memory battery which was totally kaput.  Interestingly, this battery not only keeps the 20 memories alive but also brought back to life the CB radio-style S-meter reminiscent of radios from decades ago. Other items on the testing  “to do” list will be checking power output, frequency accuracy, drift, and finally, on-air performance.  The radio will feed a ground mounted 31’ vertical with 53 radials. With the right ionospheric conditions hopefully contacts will be aplenty.

Neatly stacked circuit boards and clean layout of QRP++

Unfortunately, no service manual exists for this gem, but it rates a 4.1 out of 5 on the eham.net Richter scale, and a number of ops have published helpful information on problems, solutions and modifications.  Notably the first run of these radios was later replaced with improved models boasting higher performance via a custom designed mixer, so knowing the serial number of your unit helps to determine if yours was an upgrade.

Rear panel control layout. Power is adjustable and tested at a hair under 5W.

You can read and see more photos from the author, Mario Filippi N2HUN, at https://www.qrz.com/lookup/n2hun

Click here to read this article on the DVRA website.


Thank you, Mario, for sharing this article and many thanks to the DVRA for allowing us to re-post it.

I owned a QRP++ for a few years and absolutely loved it. At the time, it was one of the most portable full-featured transceivers on the market. Although it can struggle in RF dense environments like Field Day or other contests, for daily use it was very effective. I eventually sold mine to fund the purchase of the Elecraft KX1 and, later, KX3.

I always loved the simple front-panel ergonomics of the QRP+ and QRP++. It’s an incredibly easy rig to operate in the field. Plus…it has a bit of a “cute” factor, if you like radios shaped like cubes.

There is a dedicated email discussion group for Index Labs transceivers–currently, they’re on Yahoo Groups but may migrate to another platform by end of year.

In addition, SWLing Post contributor, Eric McFadden (WD8RIF), has an archived webpage with a wealth of information about the Index Labs QRP+ series.

Thanks again for sharing this, Mario! I know you’ll enjoy the QRP++ once you get it on the air!


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love