[R-390] R-390 Spectrum Analizer

[blw]

> Please share the details of your Q Multiplier hook-up with us.  Thanks.

I hooked it up per Hollow State Newsletter #24. I tapped pin one of V204. It
says that it won't affect anything, but audio is a bit lower with the HD-11.
It works well when I need it. It won't do anything to a strong station, but
it works very well on weaker ones. It pulls them right out. I haven't had to
null much yet, but I have tried to null and 'flop' over to peak like I do on
a Datong FL-3 on the RBL-5/Quantum QX Pro loop setup for LF beacons. It
doesn't seem to be as sharp that way. On the Datong, I can catch a weak
beacon in a mess of other ones, put it in null mode and null out the weak
one that I want to ID. Then, I just hit the peak button and that station
pops out louder and much, much better. The HD-11 is no Datong FL-3, but it
is simple and works using two sides of a 12AX7. One side for nulling and one
side for peaking. No coupling cap is needed. I think the voltage range is up
to 300 vdc. You can get these things for around $25, and it well worth the
money to peak weak stations. I'm sure the nulling will be more valuable as I
use it more. I have a QF-1, which is almost identical, but it needs
something like 160vdc for power to the 12AX7. The HD-11 is easier to hook
up.


Barry