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The venerable UHF connector was developed in the 1930’s.  It has withstood the test of time and for the most part is a good connector for HF and VHF applications in amateur radio.  It’s fairly inexpensive, has somewhat intuitive assembly, and is mechanically robust.  From an RF perspective it’s not bad at HF and VHF, but despite the UHF name it exhibits an impedance bump at UHF frequencies and is usually avoided for UHF applications.

The UHF connector suffers from two problems, in my opinion.  One is that it’s not weatherproof.  You absolutely, positively should not have a UHF connector outdoors without weatherproofing.  If you do not weatherproof it, you will have water intrusion into the connector and probably into the braid of the coaxial cable.  Weather. Proof. It.  Connectors like the N connector  (a very common connector in commercial RF applications) which sports rubber gaskets on the mating surface and within the body of the connector are weatherproof, although it’s still advisable to use weatherproofing with the N connector.

The second issue is the difficulty in soldering the braid.  The holes in the body of the UHF connector expose the ground braid and you’re supposed to solder through these holes to make a positive connection between the braid and the connector body, and provide mechanical strength and stability.  Some folks pre-tin the ground braid before inserting it into the body, others do not.  You need a high wattage iron to do this properly and the heat required can melt the dielectric in the process.  I think many people don’t solder this well and some avoid doing it at all.

K3LR demonstrated an alternative method of soldering the braid to the PL-259 in this video:

I’ve tried this technique and for the most part it works.  (I prefer to use heat-shrink tubing around the exposed soldered braid.)  However, as you can see from the video it’s not pretty as it requires increasing the diameter of the dielectric with electrical tape, and there is not a snug fit between the connector body and the soldered braid and the coax jacket.  This technique in my opinion does provide a better braid electrical connection than most mere mortals can accomplish using the proper solder hole method, as the connector is intended to be used.

I think a PL-259 connector needs to be designed for this technique.  The body of the connector should have a smaller inner diameter in order to fit the diameter of the RG-213 dielectric.  The outer part of the connector body where the braid is soldered to it could be of a smaller diameter as well and perhaps have a gnarled surface in order to promote better adhesion of the solder.  I would like to see some sort of rubber gasket employed with the threaded sleeve for some weatherproofing, however I can’t think of a good way to implement this without affecting the electrical connectivity to the body.

Unfortunately I’m more a software guy and not very good at fabricating metal parts.  Someone with manufacturing experience could probably design this connector and perhaps make a small fortune.  It’s problem waiting to be solved.

Anthony, K3NG, is a regular contributor to AmateurRadio.com.

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The FT817 successor may be announced at Dayton next year. If correct, this is about 3-4 years too late.

The ICOM IC703 is not being replaced by the 10W version of the IC7300 outside of Japan. Personally, I do not understand the major Japanese manufacturers. Surely there is a worldwide demand for a 5-10W SDR based, radio?

It seems the huge world-wide QRP market is not being well addressed by the Japanese. It is their loss.  I think they are all nuts!

Ten-Tec seem to be struggling with their latest Argonaut judging by recent price cuts. See http://www.rkrdesignsllc.com/products/transceivers-receivers/ten-tec-model-539-argonaut-vi-qrp-1-10-watt-transceiver/ .

No, personally I think we are seeing QRPers getting a rough deal of late.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

Yaesu FT991

MLS are advertising a time limited offer of the FT991 and a bundled SMPSU at £1149.95. Now there will soon be an ICOM competitor albeit with no 2m/70cm but with 4m in the European version (and arguably a better radio?) at less than £1000 in the form of the IC7300.

No, I confidently predict the FT991 will sell for less than £1000 before the year is ended.  If you are in the market for a 100W radio it is a toss-up between the IC7300 (SDR based) and the FT991. At the moment, the IC7300 looks better value.

Yaesu may announce a (long awaited) FT817 replacement at Dayton next spring but don’t expect to see units in Europe before autumn 2016 or later, is my bet.  The Yen exchange rate has vastly improved (making Japanese goods less expensive to buy) and now the FT991 has a serious rival – result is Yaesu has to drop its price for the FT991 or they lose out. My advise is wait a few months.

Roger Lapthorn, G3XBM, is a regular contributor to AmateurRadio.com and writes from Cambridge, England.

On Tuesday, I completed the plywood enclosure for the new portable lightwave receiver and mounted the optics and the electronics. My plan is to use this here on the island for some clear-air scatter / cloudbounce tests, once suitable listening locations are determined.



As with my main system, I used a homebrew mount capable of movement in three directions.


The photodiode needs to be mounted precisely at the focal point of the fresnel lens, and all three directions need to be juggled for correct alignment. Shown below is the setup used on the shop floor for alignment. The signal source is a 1W red LED about ten feet away.


I covered the photodiode with a small piece of paper which made it a lot easier to find the point of sharpest focus. Once this had been found, everything was tightened and, hopefully, locked into position.


I then constructed a simple mount which allows the receiver to be tilted in altitude so it can be set to point at the desired region of sky. Once this was done, there was nothing else I could do but wait for darkness, so that the receiver could be tested.




The fresnel lens used was purchased locally for just $5, so I had my suspicions regarding its optical quality. As well, it is 20% smaller than the bigger lens used in the main lightwave system. The bigger lens is 650 sq.cm compared to the inexpensive 'page-reader' lens of 530 sq.cm. The 2mm thick rigid plastic lens is an 'Enkay 2950-C'. The larger lens has a focal length of 20cm while the page reader has a focal length of 45cm. This gives them 'f' numbers of .78 and 1.6 respectively.

Once it was dark enough, I took the receiver to the ocean side of the house and sat down with the receiver. From here I have a clear view of the mainland coast, on the other side of Strait of Georgia. The nearest point of land on the other side of the Strait is about 20km.

courtesy: https://www.google.ca/maps/

Much to my delight, the new lens / receiver appeared to work just as well as the bigger more expensive fresnel. As I swept the receiver across the far coast, I heard about twenty different signal sources. As usual, the strobe lights on aircraft were plentiful and very loud as planes lined up to the far north to land on runway 08 at Vancouver International. These signals were about 55km away. Several planes were followed as the climbed out into the clouds further to the east over Surrey. As I lost them visually in the clouds, the strobe signals were still quite strong in the receiver. Several signals were heard coming from Washington state, including a particularly strong 'growler', repeating about every two seconds, coming from Cherry Point south of Bellingham, about 80km away. There were many signals that had no apparent visual source (to my eyes) but were easily heard in the receiver. It appears that the $5 lens is a real bargain and should work well for my scatter tests. It seemed also, that the smaller lens, having a higher 'f' number, has a narrower field of view as aiming was a little sharper than with the bigger lens.

To hear similar signals, recorded on my first receiver, go to the links at the bottom of this blog from 2014/08.

The next task will be to determine suitable listening locations here on the island. Unfortunately, the island is dominated with two high (600'+) peaks, one right behind me to the south, which will make it challenging to get a signal from one side to the other. Hopefully I can find a clear spot somewhere that will allow me to shoot a signal over the top ... and of course, the fall weather must co-operate.

courtesy: https://www.google.ca/maps/

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

The Radio Artisan group reached a milestone recently, surpassing 1000 members.  While I acknowledge some of these 1000 are undoubtedly inactive or spammer accounts, I consider this an accomplishment after starting this discussion group three years ago.  Originally intended as a support group for my Arduino open source amateur radio projects, I’m hoping to continuing expanding the group into general discussions involving DIY projects involving amateur radio and software code, Arduinos, Raspberry Pis, and open source, and in cutting edge areas such as satellites and DSP.  I’m seeing more discussions in areas like this, especially with using Arduinos to automate shack functions.  My ultimate goal is to have this group continue regardless of my projects or participation.

I’m pleased that I’ve been able to keep the group friendly, civilized and free of mode wars, politics, and other nasties that tend to pollute some amateur radio forums.  There are a lot of smart and creative people from all around the world.  It’s great when we can all share in this great hobby.  (What is a radio artisan?)

Anthony, K3NG, is a regular contributor to AmateurRadio.com.

Steve Weinert, K9ZW did a nice job sharing his take on comments from keynote speaker and ex-FCC General Counsel Riley Hollingsworth, K4ZDH from the W9DXCC convention.

Riley spoke about the need for compassion, even for those who intentionally disrupt our communications, and hinted that many disturbed individuals are veterans dealing with mental health issues. Given his previous position, he doubtless speaks from experience.

The vulnerabilities from our dependence on networked systems and the concern this is causing lawmakers fretting about a ‘Digital Pearl Harbor’ was another topic covered by Hollingsworth.

Stop by Steve’s blog and check out both thought-provoking posts.

Jeff Davis, KE9V, is a regular contributor to AmateurRadio.com and writes from Indiana, USA.