[FoxHunt] Active attenuators

[Steven Donnell WA1YKL]

Hi, Although I dont think it will solve your friend's needs, one "almost
all there" device that could be fashioned to work as an active
attenuator is this little receive converter that is/was made by MFJ; Its
meant to attach to the ant connection of an HT and provide an easy means
of receiving frequencies between 154 and 164 MHz. I picked one of these
at a recent flea, and from looking at the schematic, it would seem to be
quite easy to convert its function to an active/offset attenuator;
Simply bypass the highpass filter on the input, and add a pot to control
the level of LO injection to the Mixer.

One additional change that I would like to do would be that instead of
using the switch to select either a 10 or 16 Mhz offset/mix, would be to
add a simple timing osc circuit (3909?) to allow the LO to operate
either continuously or pulsed.. Fun project for the upcoming winter,,,.

Maybe someone will hint to MFJ to reintroduce this "converter" for a new
type of purpose,,,.

Steve

Ernie Howard wrote:

> One of our new local hunters is interested in purchasing assembled
> active offset attenuators. Does anyone here know a source?
>
> Ernie W8EH