Garey,
Sorry about the delay in my response. Time gets away from me.
I acquired the TR-4C several years ago and my normal procedure is to put a
new acquisition on the bench and run it through a simple use test. Then I
tag it with the information, working or not, and put it on the shelf for
I am looking for the light bulb holder for the light in the VFO of a C series
receiver.
Kevin
KD0ILM
kmx...@aol.com
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Richard -
OK.
1. There is NO difference in the meter circuit, no switching involved for PLATE or IDLE. You are
measuring Cathode current in both conditions, just at different levels.
2. The SAME relay contacts are used to ground the PA Cathodes in both NON-X and X-CW switch
positions,
- Original Message -
From: Donley donley...@comcast.net
To: k4...@mindspring.com; drakelist
Drakelist@zerobeat.net
Sent: Tuesday, July 12, 2011 8:57 AM
Subject: Re: [Drakelist] TR-4C Bias Adjustment
Garey,
Sorry about the delay in my response. Time gets away from
me.
I acquired the
Richard,
I think you need to find the cause of the low voltage (230V vs. 250-260V) and
fix that first.
The meter circuit does not change by switching the sideband. As Garey said it's
only
job is to choose the filter and the lamp.
The low screen voltage will certainly affect the plate current.
Kihwal -
I agree with most of what you said. The Screen voltage is slightly low, most likely as a result of
leakage in the AC-4 filter caps. But I do NOT believe it has any significant effect on this problem
as he is able to get full power in the X-CW position.
You are correct on the X-CW
Garey,
Thanks for the clarification. As always, you are the source!
As for the floating K, I think it's normal when the mode switch is in the SSB
position and the PTT is not pressed. I know you wanted Richard to measure the
voltage during TX, but I think he measured it while not transmitting
Kihwal -
When we're several hundred miles away, we are ALL guessing! :-)
Yes, the PA Cathodes are only grounded when the relay is closed.
Richard says that he has approximately -60 VDC on the Grids, which is about
right.
With the MODE switch in X-CW the relay should be closed by the
Richard -
I thought I asked this earlier, but I can't find it now. You said you can get full output from the
transmitter and read the PLATE current on the meter in X-CW.
Does the PLATE current dip at maximum output as it should? What is the dipped PLATE current when
tuned for full output?
hi Richard,
Garey must be having a late supper tonite. I just got back from mine,
so I'll chip in. Garey's helped me a lot over the yrs.
your # 1 2, indicate that you do see some idle current, and your
later measurements of voltage at the cathode resistors confirms that
shows that you do
- Original Message -
From: Donley donley...@comcast.net
To: k4...@mindspring.com; drakelist
Drakelist@zerobeat.net
Sent: Tuesday, July 12, 2011 4:25 PM
Subject: Re: [Drakelist] TR-4C Bias Adjustment
Garey,
I have gone through my list of task assignments and have
some results. To
- Original Message -
From: Donley donley...@comcast.net
To: k4...@mindspring.com; drakelist
Drakelist@zerobeat.net
Sent: Tuesday, July 12, 2011 4:25 PM
Subject: Re: [Drakelist] TR-4C Bias Adjustment
Another thought, If the meter switch is stuck reading
output rather than plate
Richard -
Does the LOAD control move in and out, physically? PULL OUT on the LOAD control and see if you get
BIAS current
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
Donley wrote:
Garey,
I have gone through
Richard -
This is what I referred to in my last message. There is no adjusting pot on the TR-4C, but the
meter is switched from Plate current to output meter. That's why I said to push and pull the LOAD
control a couple of times. There should be a hairpin shaped spring on the LOAD control
My load switch is a PUSH switch ... it does not pull. You push in for RF
output indications ... left alone for normal cathode current.
Also, lights ... on mine ... 40M Sideband X = LSB.
80M Sideband X = is USB .. you need to switch to the left (non-X) position for
LSB.
Bill, W0LPQ
Assuming that the spring is not broken!
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
William Lambing wrote:
My load switch is a PUSH switch ... it does not pull. You push in for RF output indications ...
left alone
- Original Message -
From: Garey Barrell k4...@mindspring.com
To: drakelist Drakelist@zerobeat.net
Sent: Tuesday, July 12, 2011 6:36 PM
Subject: Re: [Drakelist] TR-4C Bias Adjustment
Richard -
This is what I referred to in my last message. There is
no adjusting pot on the TR-4C,
Completed tasks.
Adjusted bias control until 0.5 VDC across cathode resistor, equals 33 mA,
three resistors in parallel equals 100 mA total bias current. Bias voltage
is -55 VDC at this point. No bias current measurement on plate current meter
(actually has been just a slight wiggle all
- Original Message -
From: Donley donley...@comcast.net
To: Richard Knoppow 1oldle...@ix.netcom.com;
k4...@mindspring.com; drakelist Drakelist@zerobeat.net
Sent: Tuesday, July 12, 2011 8:05 PM
Subject: Re: [Drakelist] TR-4C Bias Adjustment
Completed tasks.
Adjusted bias control
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