[Boatanchors] Transmitter comparisons and a question.

[Carl]

Id start by measuring the crystal current and then reducing the oscillator 
power down until the chirp stops. You may or may not have enough drive to 
the next stage.  In that case build  a SS oscillator inside the rig and use 
the tube oscillator as a buffer/amp.

Or build a SS VFO and quit wasting money on crystals (-;

Carl
KM1H



----- Original Message ----- 
From: "Curt" <rhulett1 at comcast.net>
To: <boatanchors at mailman.qth.net>
Sent: Wednesday, September 15, 2010 8:24 AM
Subject: [Boatanchors] Transmitter comparisons and a question.


> Well, had first QSO yesterday with new to me DX-20 on 40M.  As expected, 
> it
> performs about the same as the Eico 723, the two seem nearly identical in
> design and implementation.  I've read that the Eico's transformer may be a
> little more rugged.  Neither of them like HC49 crystals, which is what 
> most
> of the available FT243s are.  Both rigs chirp like a canary with the small
> HC49, but an HC6U or real FT243 produces a clean signal.
>
> The next candidate on the bench is a Globe Scout 680, which appears to be
> intact and in good cosmetic condition.  Since it uses a 6V6 as the
> oscillator, I'm anticipating even more of a tendency to chirp.
>
> My question is whether there is a way to make the HC49 crystals useable in
> these oscillators?  The seller indicated they work fine in any rig with 
> less
> than 40ma crystal current, so obviously the DX-20 and Eico 723 have higher
> than that.
>
> 73, Curt KB5JO
>
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