Drake TR4CW keying problem.

[Jeramy Thibodeaux]

The wb4hfn site has an article about this sort of problem.

http://www.wb4hfn.com/DrakeArticles/TechTips/TroubleshootingAntRealy.htm

Hope it helps!

Jeramy
kg4azt


----- Original Message -----
From: "holden" <holden at NAC.NET>
To: <BOATANCHORS at LISTSERV.TEMPE.GOV>
Sent: Sunday, June 22, 2003 9:21 AM
Subject: Drake TR4CW keying problem.


> Troubleshooting a Drake TR4CW, the break-in keying starts out working OK
> but within a few minutes it fails, the relays dropping out within a very
> short (less than one second) time after the key is hit. Relays are OK as
> PTT works fine. Looked at the relay tube 6FQ7, and the voltage on the
> grid of the relay driver is OK at first (-6V no key, .36V key down),
> then it deteriorates eventually to about -7V no key, -6V key down so the
> tube stops conducting. Found a bad VOX pot, but replacing did not solve
> the problem. All associated resistors and resistor measurements on the
> Drake chart look OK, both the 6FQ7 and 12AV6 sidetone osc tubes test OK.
> Bypassed the coupling caps in the sidetone output and relay driver
> circuits. Anyone have any hints out there? Also, the BAMA site only has
> the schematic for the TR4C, the TR4CW circuit looks to be slightly
> different in this area.
>
> Howie WB2AWQ
>
> -----------------------------------------------------------
> This list is a public service of the City of Tempe, Arizona
> -----------------------------------------------------------
>
> Subscription control -
http://www.tempe.gov/lists/control.asp?list=BOATANCHORS
> To post - BOATANCHORS at LISTSERV.TEMPE.GOV
> Archives - http://interactive.tempe.gov/archives/BOATANCHORS.html
>

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.asp?list=BOATANCHORS
To post - BOATANCHORS at LISTSERV.TEMPE.GOV
Archives - http://interactive.tempe.gov/archives/BOATANCHORS.html