[Lowfer] rx setup

[Peter Barick]

>>> eric@willow.nutstreet.net 02/14/03 09:39AM >>>
...
"  Argo has some problems but I'll work on that..."

Eric,
I haven't used Spectran, but presently use Argo b131. I've had my
problems getting it going, mostly with trying to use it on a 486 DX2
laptop. I up-graded to a P-90 and got it partially working (no waterfall
display) though the horizontal display if fine. Had some problems
getting the sound card straight w/ the BIOS on a Win95 pc. Resolved that
too. One hint w/ sound cards, to test them w/ these DSP display apps,
can use a small mic in the sound in and give a whistle, should display.
Also I found the Windows sound level controls are for audio not the DSP
app.
-----------------------------

"I'm building Lyle's LF converter."

Didn't use that one, did build the simple pre-amp. But for a time my rx
setup was dead. I found an open FET in preamp. Dunno what happened. This
was also a time I was trying to setup the Argo app. Lots-o-kun-fusion 
on that one. On rx conditions, I usually look for distant NDBs at
200KHz, when in doubt about the LowFER group, ie, lack of seeing any for
a long period.
----------------------------------

"GT-550."

Yeeks. May be some stability issues for narrow LF work. As a goal, new
or otherwise, the R-75 ICOM is likely the best buy for performance and
several are being used by the East Coast clan. Advs., Ebay, a Wanted
here or the LWCA board may help make it a reality.
---------------------------------

" Any suggestions are welcome!"
[On LF rx ants.] Well, verticals and loops are popular, the latter
being big and "tree hugging," the K9AY delta types, and smaller multi
turn varieties, be they round, square, whatever, it's the area that
matters. 

I've made several. The Burhans one that's on Mitch's site is nice and
it's a cookie-cutter app.

I've used Lyle's rx articles for ideas and made a 20-turn, 6-foot
pentagon loop using a wooden frame and no. 20 pvc covered wire. But
note, the latter is fixed tuned and feeds a ferrite transformer to match
up to the coax into the house where I use Lyle's simple preamp in Lo-Z
mode. I have found that one need not fine tune the loop when also using
a preamp with tuning as above. There is enuf gain from the loop "parked"
in the general area, as I have found. And a big point, the small loops
(5-10 feet) can be marched around the yard if a non-noisy spot needs to
be found. Big point 2, plan on having some sort of isolation transformer
should house generated noise (tvs, dimmers, buzzers) find it's way to
the feed line and onto the loop. The isolator will prevent that, just a
thought. In my case I have built-in such an object in the present
loop-to-coax line transformer.

Further, don't be concerned about wire size or type for a small framed
loop. Hook-up wire of no 30-20 is fine with some spacing between turns.
Turns, how many? Ha, 1 to 24 will work with proper C to tune it. Of
course, fewer turns, more C. A popular number might be 15 for the LF
band, more for 137. And of course, one can use a 1-2 turn pickup link as
a good match into coax. I've used that too.

GL,
Peter