[TenTec] QRP mod for TenTec Omni B?

[Carl Moreschi]

I believe this mod does in fact exist.  I know for sure because I had 
one on my old Omni V.  The mod would definitely be a resistor change in 
the ALC circuit.

Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
www.n4py.com

On 11/11/2014 5:05 PM, Neil Martinsen-Burrell wrote:
> With the upcoming QRP Fox Hunt season (one of my favorite weekly operating
> opportunities) I am interested in the possibility of using my main station
> rig at QRP power levels.  My QRP radio is an HB-1A with RIT that does NOT
> remember the offset settings when RIT is switched off and then on.  This
> means that it take a lot of fiddling to listen to a split pile-up to find
> the station currently being worked.  I would prefer to use the Omni with
> its separate offset knob and a RIT on/off switch so that I could easily
> switch between the offset and non-offset frequencies.
>
> There are google mutterings from the late 1990s in this list's archives
> about a mod that might change the range of the ALC knob from 0-20 instead
> of 25-100 watts.  Does anyone know if such a mod exists as more than a
> rumor?  On my previous Kenwood TS-520SE, there was an external ALC pin that
> could be driven with a negative voltage to reduce output power.  Is there
> something similarly simple for the Omni 546B?
>
> I can see from the schematic that R21 on the 80743 low level driver
> controls the effect of the ALC control pot, but it seems like that isn't an
> easy solution to getting down to QRP power levels, at least without some
> fiddling to figure out what value would give the appropriate minimum and
> maximum power levels.
>
> Thanks in advance for any help you can offer.
>
> -Neil KD0UKC
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