[TenTec] Argosy 525 A Mods ?

[Robert Weingaertner]

There are 2 possible fixes for this. One is to lengthen the AGC time
constant. It will still pop, but a slower time constant will keep it 
from popping as often. The other fix is to add an RF or IF gain
control to reduce front end gain so the AGC doesn't have to attack so
hard. Audio derived AGC as used in some Ten Tecs attacks more slowly
than does IF derived AGc and this is what causes the problem.

THe time constant mod was described in November 1983 QST hints and
kinks.
The RF gain control addition was in February 1986 QST, p 51 and in
QSP Classics, P 171. There was also a Ten Tec service bulletin on 
this, TN2-525. I don't have this service bulletin, but I have the 
QST references.

			73,
				Bob WB2VUF


K2ZF@aol.com wrote:
> 
> In a message dated 4/8/00 11:27:27 PM !!!First Boot!!!, Gdn1@rocketmail.com
> writes:
> 
> <<
>  Hi,
>  I just bought a Argosy 525 (analog) and it appears to be a
>  great rig in most aspects, the only change I'd make at the
>  present is perhaps a bit faster AGC attack. I seem to get a
>  bit of a 'pop' when receiving the first character of a
>  strong CW signal. I wonder if anyone has a URL etc for any
>  mods ? ... Also would like to find the 10 amp magnetic
>  breaker for use on QRO (currently just use it for QRP) but
>  those appear to be quite rare :(
> 
>  73 Gary K8IQ >
> 
> Gary, I have found that many of the older Ten Tec rigs have the tendency for
> the first character of a received cw signal to cause the AGC popping sound
> you described. I found the hard way not to wear headphones when using the
> older rigs. I still have ringing in my ears from the popping AGC, hi. I would
> strongly suggest you find a mod to eliminate this problem. Good luck de K2ZF
> (Jim)

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