At 09:46 PM 11/22/07, you wrote: >--- In [email protected], "David Epley" <[EMAIL PROTECTED]> >wrote: > > > > What is your opinion on a ΒΌ wave open stub installed in the receiver >side > > cut for 104.9? > > > >David, > This is the first thing I'd try. I have much success using stubs >to eliminate problems such as yours. However, it won't help much in >the case of common mode problems which yours may very well be. >Shielding and grounding may be your best solution in that case. > > I once had a Heathkit freq counter that picked up our FM >transmitter when connected to anything. A 1/4 wave open stub and tee >at the input cured the problem. I've also used them on FM receivers at >the station to knock down our signal enough to listen to other stations. > > An open stub at the FM station's frequency hooked to your 900 >receiver will add some reactance to the line but that should not be >too much of a problem unless it comes out as an even multiple of a >half wavelength at your 900 freq. > >Al, >K9SI
And if I remember Mr. Andreano, my electronics instructor correctly, a 3/4 wave stub should do the trick, and not bother the 900mhz frequency. Just use high quality cable (i.e. heliax). Make sure the shorted end is moisture proof, I've seen one with a copper pipe cap with a hole drilled in the center to clear the center conductor... The builder cut back the outer jacket, soldered the center conductor to the outer surface of the cap, trimmed the excess, then soldered the outer edge of the cap to the outer shield of the heliax. Mike WA6ILQ
