Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang
----------------------------------------------------------------------
Paul -
Reading your message, I assume that you are able to operate the
transmitter in SEPARATE or XMTR. If so, the problem is not in the PTO.
The transceive system patches the Premixer signal (Band Osc - PTO)
signal from one to the other. So the problem is in the switching system
itself, not in either signal generation circuitry.
Enabling XMTR control involves sending a negative voltage (~ -13V) to
the receiver to disable the receiver Premixer stage (V8). Diode D13 is
a likely suspect if the -13V is present from the T-4X. Alternatively,
if the transmitter is NOT sending the -13V, the problem is in the T-4X.
The voltage is supplied via R59, _through_ the secondary of T5 and
Section 2 Rear of the TRANSCEIVE switch.
73, Garey - K4OAH
Atlanta
Drake 2-B, 4-B & C-Line Service Supplement CDs
<www.k4oah.com>
Paul Havlik wrote:
I'm hoping someone on the reflector may be able to point me in the
right direction on my Drake T4X. I picked up a T4X/R4B pair through
a swap. As I've cleaned it up and retubed the rigs, I've encountered
a problem with the T4X switch that switches the radio from the
receiver VFO to the transmitter VFO.
I cannot obtain any "switch" to the transmitter VFO for it to become
active and work in the transmitter position.
The radio has been totally retubed and contacts cleaned with the good
deox spray and I have all new working cables back to the receiver.
The receiver works fine, the transmitter output works fine, but I am
unable to use the separate transmitter VFO as a receiver. In the
transmitter position, all I hear and can control is the receiver VFO.
I have also checked the anti-vox from one of the website articles and
that setting has no effect on the relay firing to energize the
transmitter VFO.
I'm sort of stumped at this point wondering whether I need to begin
looking at the transmitter VFO solid state components as to why I'm
not hearing anything or having any control over that transmitter VFO
for receive. Or, is there some relay inside the receiver that is not
"handing off" back to the transmitter VFO when I move that switch? I
have received a signal from the spot position on the receiver VFO when
moved to that position.
I'd appreciate any ideas that can be provided. This is my first time
tackling a restore on a Drake beyond very common problems.
Thanks.
Paul
[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
----------------------------------------------------------------------
Submissions: [email protected]
Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body
Hopelessly Lost: [EMAIL PROTECTED] - help in body of message
Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net
----------------------------------------------------------------------
