TR3 LSB problem

Bob Login jlogin at MINDSPRING.COM
Thu Oct 21 11:36:13 EDT 1999

Hi -Have a TR3 I'm restoring and could use some help.

I have a TR3 that I just obtained. Vy dirty but after clean-up and cleaning
of relay, worked quite well on rx but not on tx. Changed several weak tubes
6EA7's got power out only on cw
and USB but very weak on LSB. Tried to adjust carrier balance and associated
circuits with no effect. Thought that diode in balanced modulator may be out
but resistance measurements are the same (40k) on each leg. Feeding in a
from the Heathkit SB610 thru the mic jack gave the expected waveform on usb
but a
much reduced waveform on lsb. No adjusting of the balance pot or the
variable caps
near it seems to have an effect? C130 the bfo control next to the balance pot
 also seems to be not working as I cann't get the noise to the same pitch
as I rock back
 and forth from USB to LSB. Worried that the lsb xstal filter is broken?

Any thoughts on my TR3....Tnx & 73 Bob, AA8A

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