[Drake] TR7 Audio Problem

Tue, 19 Mar 2002 16:59:24 -0800

Duane....have your friend try this....should fix it.
	Cheers 
		Dave K6XYZ

>>From Bill Frost:

"The fixed passband controls are located on the power supply board of
the TR-7.  Remove the wrap-a-round cover of the TR-7, the power supply
board is located in the right front corner.  You will see five small
"blue" controls along the top of this board.  They are in the same left
to right sequence as the "mode" switch.

	The left most control (you are facing the TR-7) is the AM
control, next (going to the right) is the RTTY control, then the CW
control, then the LSB control, and last the USB control.  The control to
the far right (sometimes a "black" control) is the 10 volt adjust
control DO NOT BUMP OR ADJUST THIS CONTROL ! !

	Once you have become familiar with the controls and their
location, proceed as follows:

	1. Select the desired mode to be aligned.

	2. Ensure that the PBT button is released.

	3. Tune the receiver to the exact frequency which corresponds
with the desired mode.
	AM = 13695.0
	RTTY = 13697.5
	CW = 13694.2
	LSB = 13696.4
	USB = 13693.6

	4. As the receiver approches the desired frequency, a beat note
can be heard.  The beat note should be zero when the receiver is on
frequency.  It maybe necessary to increase the audio gain since zero
beat will be on the slope of the filter and weak.

	5. If the beat note is not zero, adjust the corresponding PC
control for zero beat.

	6. If additional modes are to be inspected, repeat the above
procedure."<<<

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Duane Fischer, W8DBF
Sent: Tuesday, March 19, 2002 4:56 PM
To: [email protected]
Subject: [Drake] TR7 Audio Problem

A friend has a Drake TR7 with an unamplified D-104 mike. The CW output
is good and the receive seems adequate. The match to the G5RV is good.
The mike is the
correct impedence for the TR7. 	

When he tries to operate in the SSB mode, the recieve seems to be
slightly off the indicated frequency. The audio quality of the
transmitted signal is thin and intelligibility is poor. Listening to it,
it almost sounds off frequency
slightly. Even tuning his SSB signal with rit does not clear it up much.

Any suggestions as to what might be amiss? The balanced modulator?	

The transciever has been professionally refurbished and checked on the
bench. It was not tested on the air by the man who did the work, being
as he is not
licensed above a Technician.	

Your thoughts and suggestions would be appreciated. I will foreard them
to the
gentleman with the troubled TR7. Thnks so much. 	

Duane Fischer, W8DBF	
[email protected]
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