[Antennas] Re: B&W window antenna

Wed, 3 Apr 2002 21:26:00 -0500 (EST)

 Hi Dan and Bob:

   I have the old B&W window antenna (one coil per band) and the new one (one coil with a tap wire).  I found the original to be easier to operate if I just wanted to use one band, otherwise it had to be taken apart each time to change bands.  Both antennas worked equally good when both the counterpoise and tap were properly used.  I was really surprised how good they worked even on 40 meters if you mounted it on a metal railing and stretched out the counterpoise.  100 watts and I worked all over the world.  Whatever SWR was present was easily manageable with the built in tuner.

   As Dan points out, SWR shouldn't be the only consideration when evaluating an antenna.  However, in this case it provides some indication as to whether or not the antenna has been properly assembled.

   Ron W7MRR

--- On Wed 04/03, Dan Richardson  wrote:
> Why oh why do so many judge an antenna by the SWR? No matter what the 
> experts say AND PROVE... Still solely judged on SWR?
> 
> Danny, K6MHE
> 
> 
> At 07:01 PM 4/3/2002 -0500, you wrote:
> >Just some of my own input here.
> >I had the chance to help a local ham try to get his B&W window
> antenna to hum.
> >We tried everything and the best SWR on 20 meters was 4.1 to 1.
> >We then tried a tuner and could not get below 1.7.
> >We added grounds and 2 more radials.
> >We then tried the 40 meter and the instructions said to leave the wire
> for
> >the tap OFF or hook it at the end of the coil.
> >Same problem.
> >SWR was better at 3.1 but at least we got it down flat with the
> tuner.
> >But a tuner should not be needed.
> >Now my home brew window antennas I had great difficulty finding the
> sweet
> >spot on the coil for a low SWR but I did find it and the SWR was 1.3
> and also
> >was taken down lower by moving the radial..
> >We went back to the B&W and added 2 turns to the coil and we moved
> the tap
> >just short of 1 full turn.
> >BINGO!! we had a 2.1 SWR.
> >Playing around we got as low as 1.4
> >I think I'll keep with my 9 foot job I built the first time.
> >Tomorrow B&W gets a call and I want to know why we had to add 2
> turns or if
> >it was a factory defect.
> >I have not seen the MFJ but it has a 4-1 balun built into it but I
> can't seem
> >to get any info on it.
> >So if you feel the need for a short antenna and want to work DX build
> your
> >own or just use a mobile stick..
> >The coil on my home brew has 50 turns and tapped appx 2.5 turns up
> from the
> >bottom.
> >That gives me a flat SWR and I have a full 75 KC on 40 meters and the
> SWR
> >climbs up to 1.3.
> >Close but no cigar.
> >Remember if you want to build one they work great but the taps are
> very fussy.
> >I used a needle to tap # 18 GA RS speaker wire.
> >I has a noise bridge in line and when that started to settle down I
> put the
> >SRW meter in line.
> >A lot of fun and you can bag world wide DX with them as many have.
> >But B&W in the past had a coil for each band and I feel thats
> where they
> >screwed up.
> >I guess as i'm not an EE.
> >I just assume.
> >As it stands right now i'd rather have a coil for each band.
> >Anyone have this problem with the B&W?
> >SAVE$$$$$$$$$$$$$$ and build.
> >Bob
> >AF2Qrp 
> >- - -
> >
> >Your moderator for this list is:
> >Larry Wilson KE1HZ [email protected]
> >_______________________________________________
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> 
> 
> - - - 
> 
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
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