Re: {Collins} Tuning the 30L-1

Thanks, David.

Someone else emailed me privately saying "The 0 on the meter for tune can be calibrated for correctness. It is adjustable and may be off.".

(To digress for a moment... It seems that the normal procedure on this reflector tends to emailing the OP privately rather than posting answers to the reflector.  While I can see that for instances where the conversation is beginning to drift off-topic, seems that for direct answers to questions, posting to the reflector would be more productive, does anyone disagree?)

I'd be curious as to the method for calibrating the zero-tune method.  My manual is completely silent on that topic.

But, as long as the tune-for-maximum method works...

This amp has older RFP 811A tubes and the YK board.


----- Original Message -----
From: "David Harmon" <k6xyz@xxxxxxxxxxxxx>
To: "Rick Poole WA1RKT" <wa1rkt@xxxxxxxxxxx>, "collins" <collins@xxxxxxxxxxxxx>
Sent: Saturday, November 1, 2014 5:21:52 PM
Subject: RE: {Collins} Tuning the 30L-1

Hi Rick.....
I think most everyone would agree to ignore the Collins 'zero tune' method.
Even if calibrated the meter ckt reacts differently on each band so it is
unreliable to use.
I don't think it is necessary to check any components.....just use a
wattmeter and tune it  your way.
With 811A tubes I would set the load to about 2.5 then drive to 300ma and
quickly dip the plate, then drive harder and load to 600ma.
The load control will vary with the band and load.
For 80mtrs my load control is 3.5.
My amps have Svetlana 572B tubes and the YK power supply replacement board.
I load my amps to 300ma then drive and load to 800ma max while observing the
watt meter.


David Harmon
Sperry, OK

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