[TenTec] ARGONAUT 509 SIDETONE

[Wa4aos at aol.com]

Hi,

The problem can be one of several different components in the sidetone 
circuit but before you heat up that solder iron, try a little DeoxIT cleaner on the 
tone and level pots, " R 5, R7," in the sidetone circuit. 
Spray a very small amount into the pot and rotate each through it's rotation 
several times then take a listen. 

If you don't have any DeoxIT try rotating each pot to a different position 
and recheck. If one of the earlier owners was a smoker, or even if not, an hour 
cleaning connectors and switches with DeoxIT can make a pleasant improvement 
in the overall operation of the unit.
 I am always pleased with problems solved and improved performance by using 
this product.

DeoxIT is a product of CAIG labs and one place to get it is from Parts 
Express, 800 338 0531. The price for a single can is about $9.00, a little pricey 
but fine product.

If that doesn't help, you might check the voltages on Q2 on the audio board 
for starters. I did once replace Q2 for one of my Argo 509's but in that case I 
didn't have sidetone at all. The voltages for Q2 are listed on page 3-17 in 
the 509 manual. If you don't have a manual, let me know and I will send them. 

Good thing is that board is easy to access and very easy to work on. You can 
remove the four screws on the bottom panel and slide it back to access the 
audio board located on the bottom left side as you face the front panel, "as I 
recall."

The Argonaut is a fine rig to say the least. Often criticized for the plastic 
side panels and vinyl covered top panel but don't let that discourage you. In 
it's day it sold for a little over $320.00 which was an excellent price 
compared to other much more expensive rigs. 

 I am collecting Break/Fix data for a possible web page that I might post. I 
would appreciate hearing back from you with your resolution.  Good Luck..

73,

Glenn WA4AOS