David,
How much dbm antenuation do you need?
I just made a 1/4 wave length open ended stub a few minutes ago.
I put hooked it up to a HP8920 tracking genarator with spectrum analyzer.
I think you can get 20 db antenuation with a T connector and open end stub
tuned
on the broadcast frequency.
Just a thought!,
Jack
----------
> From: David Wright <dwright@microagesf.com>
> To: 'NW9G' <nw9g@netusa1.net>; 'k1ky@bellsouth.net'
> Cc: 'tentec@contesting.com'
> Subject: RE: [TenTec] Ten Tec / Antenna puzzle
To: <tentec@contesting.com>
> Date: Tuesday, December 09, 1997 10:02 AM
>
> You guys should try living next to a 50kW AM Broadcast station (1 mile
> away with no obstructions.) The "lobe" is even pointed in my
> direction!!! I don't even have to have a radio to listen to them. They
> come in on my modem, phone lines, etc.
>
> Luckily my Omni VI+ can deal with it on most bands (amazing, congrats to
> the Ten Tec engineering/design team!) That alone is a heck of a
> statement for anyone wondering about the Omni's receiver. I would be
> very curious if anyone knows of a HIGH power (2-3kW) broadcast filter so
> I can get filtering AND continue to use my Alpha amp...? Apparently ICE
> only makes < 300w models....
>
> Thanks,
>
> Dave - KB6JOX
>
> >----------
> >From: Tom Delker[SMTP:k1ky@bellsouth.net]
> >Sent: Monday, December 08, 1997 5:07 PM
> >To: NW9G
> >Cc: tentec@contesting.com
> >Subject: Re: [TenTec] Ten Tec / Antenna puzzle
> >
> >Re: Broadcast interference on the Argosy - high dipole.
> >
> >I have a similar situation with an Omni D and my high 80/40 dipole. It
> >doesnt happen with the Omni 6. Bottom line, there is a nearby AM
> >broadcast station on 1010Khz 5KW daytime, 500w night that puts a 100mv+
> >signal to my radios. The worst thing is to try and use my MFJ antenna
> >analyzer, which is useless.
> >
> >Imagine it has to do with front end mixing/overload susceptibility of
> >the particular radio design. The solution: spend $38 and purchase an
> >ICE broadcast filter. They make 4 models, (2 high power 300w and 2 low
> >power not intended for transmit) with a 1.8Mhz cutoff and the other is
> >3.5Mhz cutoff. I now have high power units in line right after the
> >transmitters and of the lower power/receive units on my beverages. I
> >believe the rejection is 25-40 db in the 160m band and it gets better as
> >you fo up in frequency. Now I can use my antenna analyzers again and
> >the Omni D is happy on the dipole.
> >
> >As to why only on the dipole, I imagine the other antennas you have are
> >higher Q in their respective bands and you will find they dont pass as
> >much of the broadcast RF back down the pipe!
> >
> >--
> >Thomas M. Delker - K1KY CFO#395 - Smyrna / Gallatin / Short Mtn. TN
> >C.A.T.S. (W4CAT) - 147.30 (114.8) / 145.23 / 223.98 / 444.45 & 444.65
> >Stones River A.R.C. (K4FUN) - http://www.Voy.net/~rfi/stones.html
> >Tennessee Contest Group (K4TCG) - http://geo1.tdec.state.tn.us/tcg.html
> >Fistfighters United Nashville (NT4L) 146.955 (114.8)
> >
> >--
> >FAQ on WWW: http://www.contesting.com/tentecfaq.htm
> >Submissions: tentec@contesting.com
> >Administrative requests: tentec-REQUEST@contesting.com
> >Problems: owner-tentec@contesting.com
> >Search: http://www.contesting.com/km9p/search.htm
> >
>
> --
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