Topband: AM broadcast tower and 160m dxpedition

Tue Jun 10 09:25:31 EDT 2014

Hi Dado:

I agree with you.  Thanks to advice from AA1K, I built a sloping dipole at 200 feet for 80m in HH7-land.  I was really loud into EU and USA with only a borrowed TS-50.

We are still looking for operators for the HH2 160m dxpedition Dec1-Dec8.

73

Dale - N3BNA

P.S.  I am forever sad about the time that I tried a sloping dipole on 160m from HH7.  It was the last day of my trip.  We finished the antenna after dusk and put it up.  It was my chance to be loud on 160 and make many people happy (I even had an argument that i should not do this because it was in a remote area and we had to fly at 6:30 AM).  So it was Friday night and I tuned around 1812 and there I heard SSB signals..then all the band was full of SSB signals. W1 stations working W2 stations and W3 stations working W4 stations.  I could not break the pileups.  I could not get any answers to my CQ calls.  My one night to be on 160 with good antenna was lost because of the SSB contest!

>________________________________
> From: Dragoslav Balaban <dado at prijedor.com>
>To: 'Carl' <km1h at jeremy.mv.com>; Gary at ka1j.com; Topband at contesting.com 
>Sent: Tuesday, June 10, 2014 7:02 AM
>Subject: Re: Topband: AM broadcast tower and 160m dxpedition
> 
>
>hi all,
>
>As I can can see in EZNEC, simple model, Tower 2 Ft over average ground, 242
>Ft high, 
>best and simplest solution is to put sloping Dipole, K8UR style, Arch shape,
>from top of the Tower, 
>
>Gain in dipole direction can be as much as 3.84 dBi at 17 degrees Vertical
>angle, 
>
>one Dipole toward EU 60-90 degrees,  and  maybe other to west 270-300
>degrees,
>
>that would cover all 360 degrees , with F-S 90 degrees  less then 3 dB
>difference, but 90 degrees from HH north is NA, south SA, and thats
>close-almost local,  so should be no problem...
>
>73 gl,    looking forward HH , would be new one 160m hi
>
>dado E74AW
>
>
>
>-----Original Message-----
>From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Carl
>Sent: Wednesday, 26 February, 2014 01:44
>To: Gary at ka1j.com; Topband at contesting.com
>Subject: Re: Topband: AM broadcast tower and 160m dxpedition
>
>Make them shorter and they will often do well over tidal marshes but not
>over open water.
>
>For a 240' tower Id suggest gamma feeding it up at the 1/4 wave point and
>use 4 elevated radials. It the AM BCB radials are installed they will make
>an excellent ground screen but do not connect them to the 160M feedline.
>
>Carl
>KM1H
>
>
>----- Original Message -----
>From: "Charlie Cunningham" <charlie-cunningham at nc.rr.com>
>To: <Gary at ka1j.com>; <Topband at contesting.com>
>Sent: Tuesday, March 25, 2014 5:24 PM
>Subject: Re: Topband: AM broadcast tower and 160m dxpedition
>
>
>> That's not so surprising Gary !!  te Way the Beverages and similar 
>> slow-wave
>> antennas work is that they depend on the lossy GND  underneath for their
>> operation, so a salt marsh would not be a very beneficial GND structure
>> under a Beverage!
>>
>> 73,
>> Charlie, K4OTV
>>
>> -----Original Message-----
>> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Gary
>> Smith
>> Sent: Tuesday, February 25, 2014 5:09 PM
>> To: Topband at contesting.com
>> Subject: Re: Topband: AM broadcast tower and 160m dxpedition
>>
>> My Inv-L is on a salt marsh on Long Island Sound in Connecticut & I
>> ran two bidirectional 860' beverages over the salt marsh. I had
>> terrible results with the beverages, very noisy and hardly any
>> improvement over the Inv-L, much of the time the Inv-L was more
>> effective on Rx. With that, my experience of beverages & salt marshes
>> says to avoid this route.
>>
>> I ended up with a HI-Z Triangular array for Rx and it works very well
>> at the same location.
>>
>> Gary
>> KA1J
>>
>>> No, I don't believe 240' is too high - especially if the tower has a base
>>> insulator!  It would be so close to 1/2 wave on 160, that it could be fed
>>> very well as a 1/2 wave radiator on 160, either via a parallel tuned tank
>> or
>>> a 1/4 wave of perhaps 450 oh ladder line. A 1/2 wave radiator wis an
>>> excellent transmit antenna, and, because of the high feed-point impedance
>>> can be driven against a very modest ground arrangement
>>>
>>> Like you, though, I believe they would do well to put up some terminated
>>> loops, or perhaps a Beverage (or 3?) for receive antennas! A 240' 
>>> vertical
>>> would, I think,  be a VERY noisy receive antenna. If they put up a KAZ
>>> terminated loop that only requires one overhead support, they could steer
>> it
>>> around with ropes and weights on the ground. The KAZ is like ON4UN's
>> FO0AAA
>>> 160 receive loop.
>>>
>>> 73,
>>> Charlie, K4OTV
>>>
>>> -----Original Message-----
>>> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of 
>>> Richard
>>> Karlquist
>>> Sent: Tuesday, February 25, 2014 3:38 PM
>>> To: topband at contesting.com
>>> Subject: Re: Topband: AM broadcast tower and 160m dxpedition
>>>
>>> Congratulations on your adventure.
>>>
>>> In the past, I have seen some of these AM tower efforts
>>> ruined by lousy receive conditions.  I suggest you
>>> get an advance team out to the site to check
>>> out the noise level etc. and maybe put up some
>>> temporary beverages, loops, whatever and LISTEN
>>> on them.  Use WWV and WWVH on 2.5 MHz as a beacon.
>>>
>>> Others can comment on whether 240 feet is too high.
>>>
>>> Rick N6RK
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>>
>>
>>
>>
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