[TenTec] Re: ARGONAUT 515

[Wa4aos at aol.com]

Hi Glenn,
 
I just bought an Argonaut 515 (SN 0022), and it looks like it needs the
ubiquitous PTO rebuild because the tuning is very stiff.  I popped the covers
to look at the PTO, and it's not an "open" one like in the 509 I have so my
question is:  "How do I get it out of the radio?".  I suspect the front
panel has to be  removed, but I thought I'd ask before taking any
unnecessary steps.
 
I also notice a popping noise in the audio when I key the rig on CW.  My
guess is that the receiver isn't turning off soon enough before the
transmitter comes on.  Have you ever heard of this happening, and if so,
what is causing that to happen?  (C1 on the Control Board is my first
suspect, followed by Q1-6).  Is your Argonaut repair log on the Internet, or
do you keep it off-line?
 
Tnx es 72,
ed - k9ew
_______________________________________________________________________
 
Hi Ed,
 
I have not put the web page up yet with my data and I was a little 
disappointed that you were the only one on the list who seemed interested. I still think 
a users, Ten Tec, Break/Fix database is an excellent idea and I plan to 
pursue this project anyway.
 
Good deal on picking up an Argo 515; those are great units and getting hard 
to find.
 
 Here is what I recommend. Take the front panel off as this will give you a 
good opportunity to shoot all of the pots and switches with DeoxIT.
It is also an excellent way to give the FP a good cleaning. I recommend using 
a product called Simple Green which is available from Auto Zone or Advanced 
Auto. This is an excellent cleaning solution and unlike 409, Simple Green will 
not soften the paint.
 
BTW, the front panel cleaning as well as cleaning the cabinet will really pay 
off. Take a few q-tips and an old tooth brush to clean the knobs as well. 
After you get it all back together you will enjoy using your shinny new looking 
515. 
 
 While you are at the auto parts place, pick up a tube of Mobile One. This is 
a synthetic grease which is high viscosity and works with high temps as well 
as high pressure. 
When you order the PTO kit from Ten Tec, take the little plastic bag of green 
grease they give you and toss it in the trash.  The green grease eventually 
dries up and fails to lubricate the brass shaft which runs through the PTO. I 
believe this is one of the main reasons that the PTO fails.
 
When you get the PTO kit in, take a micrometer and measure the depth of the 
old PTO shaft detent against the new one. In some cases the shaft is still in 
reasonably good shape and cleaning and reassembly is all that is necessary.
 
To date, I have never found any part to have failed in the PTO mechanics 
other than the wearing of the PTO shaft. Ten Tec gives you plenty of other stuff 
in the kit but you shouldn't need any of it. Either keep the unused stuff or if 
you decide to change out everything, keep the old parts just in case they are 
ever discontinued to be offered. I doubt that they will but just in case. 
 
Here is a URL to an article that I wrote in 2002 regarding the PTO rebuild of 
a Corsair II PTO. Most of this info will work with the 515 as well. Again, 
this was something that I wrote almost 3 years ago and since then I still have 
not had any of the PTO's that I have rebuilt fail. Trust me on this, I have 
rebuilt many of these. Please read this article before beginning your rebuild; I 
tried to make it humorous yet informative.
 
http://lists.contesting.com/archives/html/TenTec/2002-05/msg00125.html
 
As far as the popping when you are transmitting, check the TR diodes and make 
sure they are not leaky. I will dive into my notes and see if I can find any 
other info on this problem for the 515..
 
One other thing I like doing with Argo's is to carefully take each board off 
of it's connector mounts and clean the male as well as female pins. This takes 
a little time but I have been AMAZED at how many problems I have fixed on 
Argos doing this. Additionally, the receive sensitivity and the overall dynamic 
range usually improves. Radio Shack now has the DeoxIT cleaning tool. This is a 
device that has an abrasive shaft that pulls out of one end. As you rub relay 
contacts or in this case contact pins, the pad not only cleans like a 
burnishing tool but also puts a thin layer of DeoxIT on the pins. Very nice item and 
reasonably cheap. As far as the female connectors on the PCB's, take them 
outside and spray a little DeoxIT on each one. 
BTW, in case you don't already know, the nozzle shaft on the DeoxIT shaft 
rotates just like a faucet to increase or decrease the spray pressure. Use the 
low pressure while cleaning these pins since just a little DeoxIT is all that is 
necessary.
 
You should be able to complete all of the items listed in a few hours first 
time around. Take your time and you should end up with an Argo 515 that plays 
as good as or possibly better than it did out of the box. 
You might want to consider changing the panel bulbs out with LEDs. I 
discussed this with you before as I recall. The white/bright LEDs reduce current 
consumption and the illumination is much nicer to boot. Of course, be sure to set 
the bias for proper current consumption of the LEDs.
 
Anyway, I hope this helps, I am going to post your query and this reply on 
the Ten Tec page Incas someone else needs any f this info or if someone might 
have other suggestions.
I do believe is sharing knowledge and trust others will as well..
 
If you decide to check the alignment and need instructions, let me know and I 
can send them to you but it may be a few days before I get to dig out that 
manual.
 
Hope you and your family have a great Christmas and maybe we will run into 
each other on the air at some point...
 
72 es 73,
 
Glenn WA4AOS