[Drakelist] T4XC problem

2013-09-23 Thread Chris Pickett
hello chaps.

 

I have a problem with my Drake 4 line and would appreciate some assistance
or ideas.

 

I have a R4C and T4XC, the rx is good and the R4C appears to work normally
but the transmitter will not put out any power and when I place the
transceive switch over to the XMTR position the audio goes all warbly -
almost auroral hi.

 

The Transmitter will not put out any power at all, I get a small lift on the
meter when I initially tune but that soon goes off and I cannot replicate
it.

 

There appears to be no difference on the recovered 'Warbly' audio when I
switch between LSB  USB although the PTO does work and appears to tune the
transmitter up and down the band ok. If I attempt to tune or spot then the
tx relay chatters constantly with no discernable movement on the meter.

This also does this when I try to tune up.

 

Prior to being mothballed for a couple of months it all worked FB. The only
other change is that I ordered a new set of connecting cables when I sold my
other 4line.

 

The cables all check out OK and I have repeatedly checked the manual re
connections with to no effect.

 

I wonder if anyone has had a similar problem with any of their Drake
equipment.

 

I would be very grateful of any pointers or help

 

Kind regards, 73

Chris

M5LRO

___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


[Drakelist] T4XC Problem

2011-04-18 Thread Terry Wilkin
I have a T4XC in excellent condition that has developed a problem. I was operating a few weeks ago and notice the transmitter had moved to transmit and I had not keyed the transmitter.Before I could determine the issue, the fuse in the AC-4 blew.I have replaced the fuse and with all connections removed except a dummy load, after about 15 seconds of warm up, the relay clicks to transmit and the plate current starts to climb.I have replaced the vox,and driver tubes with no change in conditions.Any suggestions?ThanksTerry
___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


Re: [Drakelist] T4XC Problem

2011-04-18 Thread Al Parker

hi Terry,
	I hope your finals are OK, maybe you caught it fast enough, or the fuse 
blew quickly.  Sounds like the bias supply has a problem, most likely 
the filter cap, which may have blown a diode.  You lost bias, which 
affects the PTT ckt and keeps the finals cutoff.  If you lose bias it 
does just what you saw, and puts the finals into full conduction, 
melting them down.
	Don't try to power again it up until you rebuild the AC-4, the kit from 
Heathkit Shop is a good way t do it, but at least get in there and 
disconnect the present caps and fit some new smaller physically ones in 
there, for all sections.

73,

Al, W8UT
www.boatanchors.org
www.hammarlund.info

There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats
Ratty, to Mole

On 4/18/2011 11:27 AM, Terry Wilkin wrote:

I have a T4XC in excellent condition that has developed a problem. I was
operating a few weeks ago and notice the transmitter had moved to
transmit and I had not keyed the transmitter.
Before I could determine the issue, the fuse in the AC-4 blew.
I have replaced the fuse and with all connections removed except a dummy
load, after about 15 seconds of warm up, the relay clicks to transmit
and the plate current starts to climb.
I have replaced the vox,and driver tubes with no change in conditions.
Any suggestions?
Thanks
Terry



___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


Re: [Drakelist] T4XC Problem

2011-04-18 Thread Don Cunningham
Terry,
Have you rebuilt the AC4??  Sounds like the infamous bias cap failure to me.
73,
Don, WB5HAK___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


Re: [Drakelist] T4XC Problem

2011-04-18 Thread Al Parker

Hi Terry,
check the bias section, no need to get a new supply.  Drop H-K Shop a 
note, maybe he'll send you a new cap.
	You can disconnect it from the xmtr, short 2 pins on the connector 
(can't remember which ones, and don't have a skem handy), and you can 
check no-load voltages. It's possible the bias adj. pot is bad, IIRC, 
the kit doesn't include that.

73,
Al, W8UT
www.boatanchors.org
www.hammarlund.info

There is nothing -- absolutely nothing -- half so much
worth doing as simply messing about in boats
Ratty, to Mole

On 4/18/2011 1:18 PM, Terry Wilkin wrote:

Thanks Al.
I believe it was caught early in the process so the finals should be OK.
The PS was rebuilt using the Heathkit mod and lasted about 2 hours.
I will look for another supply.
Thanks
Terry


___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist


Re: [Drakelist] T4XC Problem

2011-04-18 Thread Garey Barrell

Terry -

Amost certainly failure of BIAS supply in AC-4.  Suggest AC-4R kit from 
The Heathkit Shop.


73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
www.k4oah.com


Terry Wilkin wrote:
I have a T4XC in excellent condition that has developed a problem. I 
was operating a few weeks ago and notice the transmitter had moved to 
transmit and I had not keyed the transmitter.

Before I could determine the issue, the fuse in the AC-4 blew.
I have replaced the fuse and with all connections removed except a 
dummy load,  after about 15 seconds of warm up, the relay clicks to 
transmit and the plate current starts to climb.

I have replaced the vox,and driver tubes with no change in conditions.
Any suggestions?
Thanks
Terry
   


___
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist