🚀 go-pugleaf

In article <1992Dec30.072855.8927@mel.dit.csiro.au> gre253@mis.csiro.au (Steven Green (+61 6 276 6813)) writes:
> OK. I have a NAD 4225 Stereo tuner. I also have a external 28? element
> UHF antenna aimed at the local TV (and FM radio) source 7km (~4miles) away.
> The antenna has no "line of sight" problems with the translator, however, 
> I do have a problem with ghosting, althought not bad, should be better
> given my setup. This, I am told, is caused my the proximity of the flat metal
> roof, which the antenna sits about 2m ( 6feet) above.
> 
> My problem with FM reception is as follows. I have tried BOTH connectiing to 
> the external UHF antenna, via a 75ohm coaxial cable, and using an internal
> 300ohn dipole antenna. With both I get annoying high frequency interference.
> The only work-around at present is to press the BLEND botton on my tuner
> , which eliminates the interference, but sadly, a lot of the hi-end as well.
> As I enjoy recording simulcasts of classical presentation on the public
> TV channel I would like to know how I could improve my FM reception.
> 
> Do I but an external FM-audio antenna or, as a freind suggested, raise the
> height of the UHF antenna to about 5-6m (15-18feet) from the flat metal roof.
> My feeling is the latter may improve my TV(video) signal, but is the antenna
> too selective for FM(audio) use?

FM is at the low end of the VHF band.  A UHF-only antenna won't be any more
effective than the lead-in wire by itself.  Your best bet is probably to buy
an all-band VHF+UHF antenna or add a second low-cost VHF-only antenna (or a
"FM-only" antenna if you can find one easily) several feet away on the same
mast.

Given that the FM source is only 7 KM away, you shouldn't need anything
fancier, but for fringe area FM reception an antenna with more low-band
VHF elements and/or an in-line amplifer may help, especially with stereo
reception.  Stereo requires a better signal/noise ratio and a weak signal
gives the effect you describe with hissing in stereo mode, which is reduced
with mono or blend setting.

The close proixity to the metal roof won't help matters, but get the right
antenna first...

-- 
George Robbins - now working for,     work:   to be avoided at all costs...
but no way officially representing:   uucp:   {uunet|pyramid|rutgers}!cbmvax!grr
Commodore, Engineering Department     domain: grr@cbmvax.commodore.com