Even better for 2025

New desktop publishing software opens up even more possibilities for the SARC Communicator, the digital periodical of Surrey Amateur Radio Communications. This issue is now available for viewing or download. Another new feature is a smaller version, best suited for mobile devices, available here for viewing or download. The advantage of the larger version being higher resolution graphics and photos. 

The best new feature, in my opinion, is the ability to provide you with a compete Table of Contents [below]. This should enable better accessibility from search engines. 

You will find some great articles in this issue, along with our regular columnists.

Now read in over 165 countries, we bring you 120+ pages of Amateur Radio content from the Southwest corner of Canada and elsewhere. With less fluff and ads than other Amateur Radio publications, you will find Amateur Radio related articles, projects, profiles, news, tips and how-to's for all levels of the hobby.

Download the January - February Communicator in 
LARGE or SMALL format, or read it on-line like a magazine

Previous Communicator issues:

Search for past Communicator issues

and a full searchable index is HERE.  

As always, thank you to our contributors, and your feedback is always welcome. 

The deadline for the next edition is February 15th.

If you have news or events from your club or photos, stories, projects or other items of interest from BC or elsewhere, please contact us at [email protected]

73,

John VE7TI
'The Communicator' Editor

The Table of Contents for the January-February 2025 Communicator issue:

 

Almost hit 14,000...

Once again it's year in the rear-view mirror time at the shack. I do want to start by saying I am thrilled that 2024 has come and gone with no health issues for our entire family! To me, that is the best gift of all our health. As for me I am finally getting settled into retirement and feeling the "normal" feeling. In 2025 I will hit the milestone of turning 65...funny as I get older it seems that those older than me are "old" until I hit that age and the "old" timeline moves further ahead. One area I will be working on in 2025 is my mindset. I find with all that has been going on in our globe it has started to slant me in the wrong direction. I want to make the effort to re-balance, reset or see the other side of things. I guess more of the bright side is what I am saying. 

Ok, enough of that and on to the hobby end of things......I had a great year of CW contesting. I am now very comfortable calling "CQ contest" or running as it is called. I have improved on my pileup skills, being able to pick out a call from the many that are coming at me. I have gained the art of coping ahead but it's still new and if I do not practice for a few days it slips. 

There was no real improvement of antennas here as I do live on a small lot and not much space at this time to go crazy. I did however do some computer upgrades such as an M.2 SSD  which turned out to be a great upgrade. I did have my share of RFI issues over this past year BUT finally forking out the money for quality toroids from Fair-Rite did the job. There was some fine tweaking along the way but I am confident I have now worked out all the bugs and am RFI free.....famous last words. 

Looking ahead into 2025 at this point radio-wise it looks like the same old same old but I am very happy with that. The funny thing I have noticed over the past 2 years or so around the time I changed the focus of the blog to CW only basically the readership and comments have taken a dive. I will continue to look into this and over the course of 2025 see if it is time to close the door or refocus on the content.

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

 

My path around the globe

I entered this contest as a single operator, Low power (100 watts or less) and unassisted (Did not use any spotting clusters). The radio was the Icom 7610 along with the Hustler 4BTV vertical antenna. The solar weather was great and the 24 hours came and passed with Kp1 and the Bz in the positive direction. I had zero issues with my software, radio, RFI and antenna so I am a very happy camper. The only issue I suffered from in the past has been RFI and I now feel with a few major contests in the books and no issues that the problem is in the rearview mirror.
At this point in my CW contesting ambitions I am not too concerned about my score, I want to polish my CW running skills. To do this I am not in the assisted category which means my band map is not populated with cluster spots, no decoding programs and I do very little search and pounce. I just stay on frequency and dit dit  "CQ CONTEST". I was running at 32 wpm which I find to be the sweet spot for contacts. In this contest, the exchange is 5NN and my province, which in all contesting programs would be prefilled at the listener end. If it was a progressive serial number then would program into the macro code for the number portion of the exchange to be sent slower. Stations from outside of Canada would send a serial number as their exchange and some would send at over 40wpm and that is fine by me. 

 

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

In this episode, we join Martin Butler M1MRB, Dan Romanchik KB6NU, Caryn Eve Murray KD2GUT, Edmund Spicer M0MNG, and Ed Durrant DD5LP to discuss the latest Amateur / Ham Radio news. Colin Butler (M6BOY) rounds up the news in brief and the episode's feature is Portable Antennas Data Review.

We would like to thank our monthly and annual subscription donors for keeping the podcast advert free. To donate, please visit - http://www.icqpodcast.com/donate

• How Ghost Radio Signals Could Hold The Key To Finding Missing Flight MH370
• YOTA Month Draws To A Close But Is Still Busy On The Air
• Intrepid DX Group Youth Essay Contest Announces Winners
• AM Bill Is Not Part of Congressional Stopgap Funding
• Disappointment Immediately after Liftoff
• Updated Equipment Can Save Lives
• HAMSCI Plans Conference for its 'Big Year'
• Holiday SSTV Experiment from the International Space Station
• RSGB is looking for a new Lecture Coordinator
• ARRL Straight Key Night 2025

Colin Butler, M6BOY, is the host of the ICQ Podcast, a weekly radio show about Amateur Radio. Contact him at [email protected].

Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.

It was only a few years ago Ashhar Farhan's small company HF Signals from India launched the Bitx40, a small 40m rig that was sold as a completed PCB, it was up to you how you housed it and cased it up. It sold in droves, and paved the way for the uBitx a fully functioning multi band HF rig cased, and complete, for a bargain price of HF entry to our hobby.

 Since then sBitx was developed and again opened the SDR path of development, powered by a Raspberry Pi as it's engine.

Well Ashhar has done it again! With the launch of zBitx.

 

This is what he has had to say launching it on Christmas day on the Bitx forum:

After months of work, we finally have the zBitx in production! We were able to price it at an incredible $149 USD for a 5 watt, 80M to 10 M QRP radio with a large 480x320 touch screen that allows you to run CW, FT8 and other modes without needing even the phone that the original zBitx used.

Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

Readers may recall my summertime blog, "Finding Your Best Crystal Radio ‘DX Diode'". It described a theoretical method I tried in order to see which of several dozen diodes might emerge as the best of the show, or in crystal radio DX circles, the ‘Holy Grail Diode’!

The grading system revolved around the combination of several factors … the diode’s measured forward-voltage (Vf), the weakest signal level detectable from an RF oscillator (whose level could be varied) and the diode's current when detecting a fixed-level signal on 1220 kHz. These values were used to derive a numerical ranking that I called ‘Vdx’, which would hopefully rank the best overall performers!

It’s not unreasonable to think that diodes with a very low forward voltage (Vf) combined with the ability to detect the weakest signal from the signal generator, might likely be the best diodes in the bunch … or are they?

These tests capacitively-coupled the oscillator signal directly into the crystal radio’s antenna tuner, which then coupled them into the detector stage. Using the methodology described in the earlier blog, the 48 diodes under review were narrowed to the ‘top 10’ likeliest best performers.

This time, actual ‘on-the-air’ signals would be used to compare diodes against each other in real time. A closer look at the top candidate diodes was made over several days and evenings as the days grew shorter and darkness arrived earlier.

My DX set has provisions for comparing a current good performing diode against two others.

 

In this arrangement, shown above, the current ‘best diode’ is mounted in the center switch position so that an immediate comparison can be made between it and the other two in real time.

A weak groundwave signal from Seattle, with a slow fade rate, was used initially but nighttime skywave signals were found to be most useful. Several  hours were spent tuned to 2800 watt CKBI in Prince Albert, Saskatchewan on 900 kHz. Their C&W format meant that most of the time they were broadcasting music, which I've found is always much easier for the ear-brain to detect in the noise floor than are spoken voices.

So what did I eventually find out? My original ranking methodology concluded that the best overall diode of the many dozens was the Sylvania JHS 1N3655A, a 40-year old microwave mixer diode.

The observations of the CKBI signal strength were by ear-brain only and no actual levels were measured since signal levels were usually too weak to measure on my detector's micro-ammeter. Measurements may yet be undertaken using an oscilloscope or by using an audio amplified output to compare signal voltage levels.

So … would my diode-ranking order and testing methodology hold up when actually using the diodes in a hi-end, low-loss crystal radio system when connected to an actual antenna?

I started ‘A-B’ comparisons against what has always been a reliably good performer mounted in the center position, a fairly modern twenty-year old  1N34A.

As noted above, the #1 rated diode (with my Vdx rating of 66) was the 1N3655A microwave mixer diode. Although it did not produce the loudest signal (diode current) compared with others, it had an exceptionally low Vf of .18V and its weak-signal detection level was good although not the lowest. Like a few others, it detected the nearby UHF data stream ‘clicks’ from a nearby Wi-Fi modem, often a characteristic of a good performer.

I was somewhat aghast when my #1 ranked 1N3655A was immediately outperformed by the modern 1N34A, ranked 44 out of 49! The 1N3655A was not just poorer than the 1N34A, it was very poor by comparison ... hmm ...was my selection process really that far off?

Diode #2, also with a low Vf of .197V was also poorer than the 1N34A, whose Vf was an unimpressive .375V.

And so it went for the most part, with my top 10 choices! Most of them were equal to the 1N34A but nothing stood out while listening to real on-air signals until I got to the three ‘curiosity’ diodes, originally tested at the very end.

Surprisingly, the D18 produced a noticeably better signal than the 1N34A and was moved into the #1 position.

 

These last two were both made in the 50s … was there something different about the way they were made? Was the germanium different back then? How did they perform so well when their Vf was so high? It almost appears the opposite of what might be expected.

Seeing the above behaviour, I couldn’t pass up the chance of testing the 48th ranking diode, a beautiful black NOS Rogers 1N34A, probably another product of the 50s. Its Vf was truly discouraging, at .401V and the reason I had mostly ignored it in the past. It was put up against the D18.

 

I was astounded to find that not only was the vintage black beauty better than the D18, it was a LOT better! The ‘just barely’ detectable CKBI signal popped out of the noise to become one that was easy to hear! I had to rock the ‘A-B’ switch back and forth many times just to enjoy the big difference!

Out of curiosity, I tested the last-ranking diode (Vf of .444V) and it truly was deaf, with not even a sound emitting from the phones … so at least I got that one right!

What is obvious now is that the method I used to rank the diodes was flawed. These results have brought up several questions for me that I had never considered previously … far more questions than answers!

Takeaways? I've found that there's a lot about diodes that I don't know and need to learn about! I’ve learned that a diode’s Vf value is not an indicator of its weak-signal detection capability in crystal detectors (in spite of what some You Tube videos might try to convey). I've learned that when detecting a weak signal, the diode is operating below its Vf value which helps explain why a high Vf value does not mean a poor detector or a low Vf does not mean a good detector. Low Vf values were a well considered number when ranking my diodes … an apparent mistake.

Further to this, the diode is operating within its ‘square law region’ when detecting the weak signals we seek. When operating in this region, it means that increasing the input signal by 5 times (for example) will increase its output by 25 times. Similarly, decreasing the input level by 5 times will result in a 25 times drop in output. The importance of reducing as many losses as possible in the antenna tuning stage along with the detector stage itself can certainly pay fast dividends when it comes to weak signal detection. Conversely, ignoring system losses will very quickly reduce performance.

Also ignored in my system was diode capacitance, diode operating impedance, reverse leakage and no doubt some characteristics I'm not even aware of. Diodes with lower C will have fewer losses than those that are higher. I wonder how much of a factor was this in my overall unexpected results! The diode’s internal resistance when detecting a signal is a factor that I did not consider. The method of determining this value is complex but it may explain some of what I noticed.

There appears to be something different with older diodes that makes them great performers … larger junction? Germanium quality?

A final take away ... with enough knowledge, one can measure every tiny detail about a given diode without actually using it. No doubt a ranking list of diodes going through such rigorous scrutiny could zero-in on the top few. What's the BEST diode to use? It's probably the one that seems to work the best in your particular detector, until a better one comes along ... but it appears you can't go too far wrong with a very good 1N34A ... even in 2024!

 

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].