[heathkit] zero beat

["larry allen" <larya@rogers.com>]

My first transmitter was the dx-60, as well, ... my first receiver was the 
gr-91... general converage receiver...My second receiver was the
hr-10...My vfo was the hg-10....
When you are adjusting the rf gain, you are as I recall, in effect, 
pulling the receiver's tuning slightly...
I would go the other way... set the rf gain to peak and then adjust the af 
gain appropriately... If the signal is too strong, pull back on the rf
gain but once you find the right setting leave it....
You could also be suffering from a weak tube.... which is allowing the 
pulling effect...

It has been a long time since I used my dx-60 hr-10... mid 60's...
I remember I muted the receiver, gr-91, by installing a potentiometer
between the cathode of the rf tube and ground and adjusted the control for 
best reception of a very strong signal.. mine...

It is quite possible I did the same thing with the hr-10.. modifying the 
front end to make is so insensitive that it could only hear me.. when I 
went back to receive the mod was shorted out...

Larry ve3fxq

----- Original Message ----- 
From: "Alan Beck" <becka@eastlink.ca>
To: "heathkit List Member" <larya@rogers.com>
Sent: Monday, May 26, 2008 4:18 PM
Subject: [heathkit] zero beat


> OK,
>
> I have a question.
>
> When I was using my DX-60/HR-10 station, I would call someone and then
> shift the BFO to match.
>
> The reason for this was that I could barely  hear my VFO in the RX.
>
> The manual states that to operate the receiver, I have to set the AF to
> 1/4 and use the RF Gain to adjust volume.
>
> However, when I do this, the frequency shifts slightly.
>
> When I key down, I really have a lot of signal that it makes a sort of
> ripping sound and peaks out the meter, one side stronger than the other.
>
> So, I go for the peak on the highest side. When I check the small
> signal, it is way off frequency.
>
> Anyone have a bullet proof technique to do this one.
>
> BTW, I am using a dow-key relay and muting the RX during full transmit
> mode.
>
> Alan

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