[TenTec] Need help with corsair ii

[Bob McGraw - K4TAX]

With voltages like that, it somewhat indicates that the elecrtolytics may 
need replacing.  These are the coupling caps between stages.  If the IC 
output drifts negative then the IC is reversed polarized a few mV and will 
eventually go bad, become leaky thus give an indication of incorrect voltage 
on the following stage.  Interesting that all of your voltages are high as 
compared to what they should be.  Are you sure you are measuring from a true 
DC ground point?  If not, then that could explain the error.

I am not aware of any item that I could say specifically "change this part" 
and it will correct the problem.  The challenge is to find the defective 
component and change it.  I don't advocate just changing parts to see if it 
fixes the problem.  More often than not, using the shotgun approach to 
replace parts will introduce more issues than one started with.

73
Bob, K4TAX





----- Original Message ----- 
From: <nf4r at comcast.net>
To: "." <tentec at contesting.com>
Sent: Sunday, March 24, 2013 3:01 PM
Subject: [TenTec] Need help with corsair ii


>
> I am told that my corsair ll has low audio while on the air. Was using my 
> 705
> mic.,have also tried my heil mics,with same reports. Both of these mics 
> work
> fine on my paragon. Corsair was purchased from a friend that had not used 
> it for
> 3 or 4 years. sn. is 580 02129. I am no tech but have used schematics to
> troubleshoot and did some homebrewing. Problem is I only have a foggy idea 
> of
> what I am doing. Traced mic input to audio processor board and found 
> u2a,on pin
> 3 has 3.7v instead of .9 and pin 5 of u2b also has 3.7v instead of .9 and 
> pin 6
> has 4.1v instead of 1.0. On u1 pin 5 has 2v instead of 0. This is where I 
> get
> lost and foggy. I have replaced the vfo with the n4yg board but can't see 
> where
> it should cause my problem. I know the small electrolytic
> caps go bad but not how to check them. This my first post so am sure I
> did not give all information needed.
> Thanks for any help or insight. You can reply to nf4r at comcast.net
> de nf4r Dave
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