> Hi,
>
> Steve Katz wrote:
>
> > ::Nothing's amiss, it's a really old design using active
> > differential amplifiers circa 1970's. <There is active circuitry in the
> > holdup amps.>
> > -WB2WIK/6
>
> Be happy they peak-hold kit design is not from the same year as the meter
> is..
> back in the 50's they did not know about op-amps certainly not a (LM-324)
> Quad
> uA-741.. hihi How huge would it be when the should have used tuubes
> instead...
> not to mention the power consumption..
>
> But if you use a single 9V AC adapter you just have to add 2 470uF
> capacitors
> and 2 diodes in this way you make a voltage doubler, add some voltage
> regulators and you'll never have to change batteries anymore..
>
::The reason I use batteries is because my Birds are portable (see
the little leather handle straps on top?) and rarely sit in one place. Most
of my measurements are "field" measurements, and no AC around...batteries
are very nice. I don't leave a wattmeter in the line all the time at home
-- my antennas are all matched, what else do I need to know? (It's possible
to tune your amp for maximum RFI to the stereo system in the next room. If
you have a really big amplifier, you can use instead the stereo system in a
neighbor's house, or maximum smoke detector activations in the
neighborhood.) However, I did build a battery replacement for the 43P, using
two 9V wall-warts, a cube tap (3-way AC adapter) and two isolated DC
connectors (coaxial mini-DIN). Total cost of the accessory was about $10.
-WB2WIK/6
> 73! de John PA5MS
> (changing batteries every 2 monthts too.....)
>
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