[MRCA] Antennas

[ersmar at comcast.net]

Al:

     Thanks for the dimensions.  I was pretty close when I took the 
dimensions from a Ham's web page last year for my EZNEC modeling exercise.

     I reconfigured my model to connect the two short elements to one side 
of the source and the two long ones to the second side of the source in the 
model.  The results are resonances at 6.15 MHz and 9.5 MHz.  My original 
configuration (same lengths but connected as two conventional inverted Vs) 
shows resonances at 6.05 and 9.25 MHz.  Plus the SWR at resonance with the 
Inv V config is lower at both resonances - about 1.1:1 vs 1.3:1.

     As I said last year, I can't be sure why yours is connected the way it 
is, but there doesn't seem to be much difference in SWR or resonance points 
between the two configs.

     Regarding the tuner, here's a web reference 
http://www.tactical-link.com/as2259.htm that implies that there was a manual 
tuner that was to be used with the AS-2259.  To me that means that some HF 
rigs (PRC-47?) might have had difficulty matching the oddball wire lengths 
and benefited from the matching help.   At least that's what I'm using as my 
motivation to build a tuner of sorts.

     I'll be in touch with you gents over the summer about our fieldex.  If 
you'd like I can contact my buddy, SEC for SNJ, and invite him and his 
section's Hams to listen for us again.

73 de
Gene Smar  AD3F


----- Original Message ----- 
From: "Al Klase" <al at ar88.net>
To: "Military Radio Collectors Association" <mrca at mailman.qth.net>
Sent: Friday, July 21, 2006 12:46 PM
Subject: Re: [MRCA] Antennas


> Hi Gene,
>
> Short elements are 24' 9" and the long ones 36' 11".
>
> I've always been confused by the disposition of these elements.  The two 
> short ones are connected to the center conductor of the mast, and angled 
> at 90 degrees to each other.  The long ones are connected to the outside 
> of the mast, angled at 90 degrees to each other, 180 degrees around from 
> the short elements.  So the antenna seems to be crossed Windoms rather 
> than crossed dipoles.
>
> I'm not sure how important a matching network is with a true field radio. 
> They'll about load a wet noodle.
>
> Regards,
> Al
>
> ersmar at comcast.net wrote:
>
>>Al:
>>
>>     Some time in the next couple of weeks, could you verify the 
>> dimensions of the two sets of wires on your AS-2259 for me?  I inferred 
>> their lengths for my earlier modeling efforts by taking the dimensions 
>> for another Ham's homebrew equivalent.  However, I never actually 
>> measured the lengths.  Harris's web pages on the antenna cleverly do not 
>> give dimensions.
>>     If I had the correct lengths I could model the actual antenna and 
>> build a matching network for 3.885.  Thanks.
>>
>>73 de
>>Gene Smar  AD3F
>>
>>
>> -------------- Original message ----------------------
>>From: Rob Flory <robandpj at earthlink.net>
>>
>>>Hi Dale,
>>>One problem with switching antennas is the need to retune.  That's why I 
>>>suggested another rig on the vertical.  Said rig could be under Ted's 
>>>control, maybe with another operator.
>>>
>>>-----Original Message-----
>>>
>>>>From: Radio Station KW1I <kw1i at earthlink.net>
>>>>Sent: Jul 21, 2006 7:45 AM
>>>>To: robandpj at earthlink.net, Military Radio Collectors Association
>>><mrca at mailman.qth.net>
>>>
>>>>Subject: Re: [MRCA] Antennas
>>>>
>>>>Rob and Gene,
>>>>
>>>>I think there may be room for both antennas in the new location that 
>>>>Steve
>>>>says we are likely to use this year.  This location has a lot more open
>>>>space around it.  I like the idea of both antennas at Fairgrounds.  In 
>>>>fact
>>>>there may be room for a vertical there as well.   I wonder if we could 
>>>>have
>>>>Ted's base station switch between antennas?
>>>>
>>>>Dale
>>>>KW1I
>>>>
>>>>
>>>>
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>>
>>
>
> -- 
> Al Klase - N3FRQ
> Flemington, NJ
> http://www.skywaves.ar88.net/
>
>
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