[Test-Equipment] Millen GDO question

[Richard Knoppow]

----- Original Message ----- 
From: "Mike Manes" <mrmanes at gmail.com>
To: "Richard Knoppow" <1oldlens1 at ix.netcom.com>; "Discussion 
of Electronic Test Equipment" 
<test-equipment at mailman.qth.net>
Sent: Saturday, July 30, 2011 8:37 PM
Subject: Re: [Test-Equipment] Millen GDO question


> Hi Richard,
>
> That's pretty characteristic of every GDO I've used, 
> including the
> Millen, a Knightkit and a really nice piece of homebrew 
> work. I
> think it has to do with the low VHF Q of the air variable 
> cap that's
> necessary to get a decent L/C ratio and tuning range on 
> the HF
> bands.  I've seen GDOs that are specifically designed for 
> VHF and
> UHF, and tho I haven't used one, I'd expect them to 
> overcome that
> problem.
>
> 73 de Mike W5VSI
>
   Thanks Mike, that's what I wanted to know. I think mine 
is working as it should. The low limit of the coil is given 
as 140mhz. The dial is calibrated down to 125mhz. The grid 
current shows some indication down to maybe 130mhz. So, it 
covers the range specified, just not the complete range 
shown on the dial. The next lowest range goes up high enough 
to provide some overlap.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com