Ten Tec Argonaut 5 goes to the park and then gets a new fan!

I love this radio, it works so well and is really easy to use with minimal menu settings. Then again I love all TenTec radios and have an unhealthy addiction to the brand…lol. Is it really that bad of a problem? I bought this one “for field use”, you know… like Field Day in June or POTA, but I have found things about it that keep me reaching for other radios most of the time. Let’s take a look at some of these short comings for a field radio that I like to use while doing an activation.

So I get this radio out much less for a couple of reasons… The main one is that it doesn’t have a CW keyer memories built in like the ICOM IC-705 and the Penntek TR-35 have in them. This is a big deal if you plan to activate for more than an hour or so as calling cq over and over manually can be strenuous to say the least with time. You see the keyer does something for me other than relieve me from having to pound out the CQ all the time, it BUYS me time. I am able to make log notes and fill in missing parts of the log while it is happily sending the CQ for me. This is a huge help after a quick string of QSOs and I am getting the times written down along with my usual log notes I like to make.

Quick rabbit to chase here… There is a few notable call signs for me on this page. K9IS is my first Hunter to get to 50 QSOs with me and KJ7DT has been showing up in my log more frequently lately too. The other call is the Canadian, just because he is DX…lol. Always cool to have those DX callsigns in the logbook. Now back to your regularly scheduled chat about the radio.

The next reason I don’t normally grab this radio is that it is fairly large compared to the other radios too. When I am operating in the truck, space is a valuable commodity and I am not able to spread all the gear around easily, if you will notice in the above photo I actually have the Argonaut balanced on my camera bag so it wont be in the way of logging… This actually worked out pretty well though and I think I will come up with something for the other radios to sit in the same area in the future, it was really convenient having the whole surface for my book and key.

The next reason is that the fan is crazy loud and runs non-stop even when I have it turned down to 5 watts for my QRP ops.

A little about the activation today is also in order. I went to K-2169 (my local park) and went to my quiet place at the top of the hill. As you can see, I had the place to myself as usual.

So I get parked, then start assembling the antenna and getting the coax into the cab of the truck when I notice that the cable adapter I have on the base of the antenna is loose, I am not sure how long it has been loose, but it was pretty loose today, to the point the BNC connector spun when I went to install it. This is how I found it was loose. Point here is check those screw together connections from time to time. They work loose too. The one on the back of the radio was loose too… which I thought was odd since I have only used it a couple of times so far.

Although today I didn’t need them, the BNC converter is a nice adapter to have in your kit. I could have used regular PL=259 connectors today, but I had forgot that the antenna and the radio both use them so I just used the same cable I use for the other radios and it worked great.

Another thing I have done is converted the power cable to use power-poles so I can plug it into any power source I use, which now also includes the power port in the truck too. I feel this is a worthwhile thing to do if you plan to work field ops a lot, standardization of the power connectors just makes sense.

I bought this case at the Huntsville Hamefest from Gigaparts and it is for some sort of military radio, but with a little cutting here and there and a little foam here and there it now houses the Argonaut 5 and a MFJ manual tuner as well as a wire antenna and some other miscellaneous items

Me and Roger (KG4WBI) have this obsession of printing out and binding all the owners manuals for all our radios. So I keep this one in the case with the radio and it was needed on this outing to see how to set a couple of menu items I had forgotten about.

Now for the Argonaut 5 Radio Fan…

The fan on this radio is just plain loud, that is the only way you can say it. It is also wired to run non-stop for some reason. This is also a pretty large current drain for no real reason at all other than to make absolutely certain the finals don’t get too hot… At some later point, I plan to make a small thermal sensing circuit that will fire a relay to cycle the fan instead of it just running all the time. but first things first, I am changing the fan itself with one of the low noise fans that another op from a TenTec group shared and it worked really well for them. I downloaded a sound meter app for my phone to see if it was measurable and have the two meter readings to see for myself. Ignore the AVG and MAX values, I watched the meter for a few minutes and did a screen capture of what was really going on to get a more representative number. 65 seems pretty low, but when you are listening for signals near the noise floor, every dB matters so the new fan comes in at 45(44.9 is what I captured in the screenshot and this was a pretty good average from what I watched on the meter.) Now also remember this is an iPhone app and not a legit sound meter, but it does give us something to look at for reference. If it is right, which is possible, then this is a 20dB difference. This is huge as decibels are logarithmic in nature and not linear, this is equal to 100 times quieter! That is awesome and totally worth the effort! To the ear, this new fan is dead silent, I didn’t think it was even running when I turned the radio on actually. So I am really pleased with how this mod turned out, the radio has one less detriment to keep me from using it at parks!

Old fan measured right at the back of the radio.

New fan measured in the same place as the old fan, that is a 20dB change!!!!

This was the ham shack with the Argonaut turned off for reference.

Orderd this little guy from amazon and had it in a couple of days.

This fan is literally a plug-n-play replacement for the factory fan in the radio. I literally removed the case screws, the fan screws, one wire tie on the wiring harness and unplugged the fan. It was the easiest mod I have ever done to a radio…ever.

Something of note, this new fan is thicker and the old screws would not work in my application, but I had a couple of screws in the junk drawer that were about 1/4” longer that worked great so I am back in the game!

The fan connector is a standard computer fan plug so it doesn’t need anything special at all. This is refreshing as it seems everybody wants to use proprietary connectors these days for some reason.

All in all, this has turned out to be a great little excursion in more than one way. I got the Argonaut on the air and I also got the fan upgraded afterwards too. I really like the ergonomics of the little machine so I will see how I can fit it into my regular activations and use it more now. Do you have a radio that you love, but just dont use because of some little issue? Let’s hear what it is and see if I am the only guy that does this.

72

David

WK4DS