[Heathkit] Fw: GB> HW-100/101 info needed for handi-ham

[Tom NØJMY - AAR7FV]

----- Original Message ----- 
From: <Wd4nka at aol.com>
To: <tfarl at mchsi.com>
Cc: <glowbugs at piobaire.mines.uidaho.edu>
Sent: Sunday, January 09, 2005 1:03 AM
Subject: Re: GB> HW-100/101 info needed for handi-ham


> Take a look at a couple things: the usb/lsb/cw osc. is
> a dual triode, on side has the LSB xtal, the other the USB
> which also is used for CW.  The way it's suppose to work
> is the keying relay mutes the receiver, and on CW the
> sidetone kicks the vox which is how you set the break-in.
> More than likely why LSB is fine, but USB and CW is acting
> up.  In CW, the balance mod. is made imbalanced to allow
> a carrier, which is why you have CW, but if the sidetone does
> not cease for some reason, the vox will keep the receiver
> muted.  How does the sidetone stay on even after key-up?
> One way is a wrong substitute tube in the sidetone circuit.
> I think it's a 6EA8.  I subbed a 6U8A in there once, and lo
> and behold: a slight sidetone was present in the cw position.
> When i keyed, it was much stronger, but unkeyed, an
> attenuated tone remained.  I then used a 6GH8, which had
> much less sidetone present on key-up.  6EA8, no sidetone
> whatever on key-up.  The 6U8A could be made to work, but
> i had to re-adjust the vox timing and put a pot in the sidetone
> ( which, btw, the SB100 - 101 already has.  The hole is
> present for one in the HW, all you need to do is add it as per
> the SB100.  I did that because the initial tone on my HW was
> way, way too loud.)
>
> Check the USB position on the mode switch for a cold solder
> joint. I have had to re-touch those contacts with a soldering
> pencil in the past for problems much as you describe.  The
> USB connect jumps to the CW connect, too.  So those are
> four areas to investigate: the oscillator, the vox, the sidetone
> and the mode switch.
>
> Hope this might point you in a helpful direction.  Hard to
> concentrate at 2am.  :>)
>
> Good Providence in all your endeavours.
> gary // wd4nka
>
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