[Drake] T4XB T/R Relay hangs

Sun, 21 Dec 2003 19:09:10 -0800

Before you do that, try adding a piece of scotch tape under the relay
armature to add a little residual gap between the armature and the core.
You can add several pieces to see if that will help any.
However, after looking at the schematic, I'll bet that the relay coil
has shorted to ground....not enough to operate the relay without help
from the tube, but enough ground to keep it operated after the tube
stops conducting. The relay has 250vdc on it all the time. If you remove
the tube and the relay does not release.............that's it...the coil
has gone to ground.

Regards

Dave Harmon
NSRCA 586
[email protected]
Torrance, Ca.

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Peter Veach
Sent: Sunday, December 21, 2003 6:39 PM
To: [email protected]
Subject: Re: [Drake] T4XB T/R Relay hangs

Ok, I tried the reversing the wires trick and it had no effect on the 
problem. I have a photocopy of the manual, but the only schematic 
included is for the power supply. The 6EV7 tests good on my sencore 
tester, but I will order a new one anyway. I have not used this rig for 
a while, but this was starting to cause problems the last time I used 
it. It seemed like the last time it did this, after a while the problem 
went away, so maybe the tube. Kinda weird though. Unless the relay is 
bad and that thing does not look like fun to replace. 

thanks

-Pete

-----Original Message-----
From: "Al Parker" <[email protected]>
To: "Peter Veach" <[email protected]>, <[email protected]>
Date: Sun, 21 Dec 2003 18:58:43 -0500
Subject: Re: [Drake] T4XB T/R Relay hangs

> Hi Pete,
>     Could be the 6EV7, could be it's cathode bias resistor.  Could be
> if
> you adj the bias slightly you'll fix it, or the anti-vox pot.  The
> esteemed Barry Ornitz has suggested that swapping wires to the relay
> will
> counteract the residual magnetizm that may have developed.
>     You oughta have a schematic/manual.  The ones on BAMA, or 'most
> anywhere else on-line, are poor resolution, the originals skems
> weren't
> very good to start with.  Let me know if you can't get a decent one,
> I'll
> send you a good scan.

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