[net.ham-radio] Accessories for SWL

luria@ucbvax.ARPA (Marc Luria) (03/19/85)

I bought a Uniden 2021 a couple months ago and have been relatively happy
with it.  Strong stations like BBC, HCJB, etc. I pull in with no problem 
and I have listened to Kol Israel's programs regularly though the reception
on that has been considerably weaker.  I have not been able to pull in Israel's
Home service at all.  The question I have is what things I could do to make
reception better.  I now have a piece of Radio Shack 18 gauge copper wire 
strung uup along the side of our apartment building.  Should I try to put
an antenna on the roof of our two story building, an active antenna, add a
preamplifier or something like the Grove minituner?  What would be most
helpful? And what brand of product?  Any other suggestions?

parnass@ihu1h.UUCP (Bob Parnass, AJ9S) (03/20/85)

       Outdoor Antenna vs. Indoor Active Antenna, etc.

Without	a doubt, putting an antenna on the roof	 will  yield
the biggest improvement, and at	a lower	cost per db.  I	have
an MFJ 1020 active antenna and an Ameco	 preamp.   They	 are
ok,  but  not as good as a mediocre wire antenna on the	roof
would be.

My choices for a simple	SWL antenna, in	priority order,	are:

  1.  A	coax fed trap dipole for multiple shortwave bands

  2.  an end fed long wire and a simple	SWL antenna tuner to
      match  unbalanced	 lines	(MFJ  or Grove Minituner III
      [$39]).

  3.  Center fed Zepp, of length = 468/[lowest freq you	want
      to  cover	 in  MHz], parallel feed line (good grade of
      jacketed twin lead), and antenna tuner to	feed  balan-
      ced line

> I bought a Uniden 2021 a couple months ago and have been relatively happy
> with it.  Strong stations like BBC, HCJB, etc. I pull in with no problem 
> and I have listened to Kol Israel's programs regularly though the reception
> on that has been considerably weaker.  I have not been able to pull in Israel's
> Home service at all.  The question I have is what things I could do to make
> reception better.  I now have a piece of Radio Shack 18 gauge copper wire 
> strung uup along the side of our apartment building.  Should I try to put
> an antenna on the roof of our two story building, an active antenna, add a
> preamplifier or something like the Grove minituner?  What would be most
> helpful? And what brand of product?  Any other suggestions?

-- 
===============================================================================
Bob Parnass,  Bell Telephone Laboratories - ihnp4!ihu1h!parnass - (312)979-5414 

Taylor.Wbst@XEROX.ARPA (03/20/85)

	I HAVE INCREASED THE SENSITIVITY OF THE 2021 BY AT LEAST 10 DECIBELS AT
~4 MHZ BY SIMPLY USING A RESONANT LOOP ANTENNA.  ALL THAT IS NECESSARY
IS TO USE THE ANTENNA WIRE THAT CAME WITH THE RCVR AND PLACE A 100 PF
VARIABLE CAPACITOR BETWEEN THE "FAR" END AND THE GROUND TERMINAL OF THE
RCVR.  (AN  AUDIO TAPE REEL, ~5 IN OD, MAKES A NEAT WAY TO STORE THE
UNUSED SLACK IN THE WIRE.)  I JUST LOOPED THE WIRE AROUND A WINDOW
BEHIND THE DRAPERIES.  

		GOOD LUCK!

			JIM (W2OZH)