[50mhz] Modifying Cushcraft A50-5S

[Carl]

Correction to the last. With 13.2 dBi translated to 11.05 dBd that antenna 
is right where it belongs on the BQH list. Boom is 1.71 w/l

Carl
KM1H



----- Original Message ----- 
From: "Carl" <km1h at jeremy.mv.com>
To: "John Kemker" <john at kemker.org>; "50mhzer's" <50mhz at qth.net>
Sent: Friday, June 26, 2009 4:38 PM
Subject: Re: [50mhz] Modifying Cushcraft A50-5S


> The T match info is right in the Cushcraft 616B Boomer manual. Ive turned 
> that into 8el with 13.2 dBi gain and 40 dB F/R without adding any boom 
> material. Thats my daily driver for almost 20 years.
>
> From what I see in the VE7BQH list posted today it has higher gain per 
> boom length than anything listed. According to YO 6.5  its within .2 dB of 
> theory.
>
> Carl
> KM1H
>
>
> ----- Original Message ----- 
> From: "John Kemker" <john at kemker.org>
> To: "50mhzer's" <50mhz at qth.net>
> Sent: Friday, June 26, 2009 4:05 PM
> Subject: Re: [50mhz] Modifying Cushcraft A50-5S
>
>
>> I've had a couple of folks send me the W5WVO mods, which I much
>> appreciate.  That lengthens the boom length with an easy mod and still
>> uses the gamma match.
>>
>> As far as building a T-Match, I don't mind, as long as there's some
>> decent instructions.  I've got plenty of 75ohm cable and F connectors
>> and am purchasing some new F female connectors next payday to finish a
>> 160m RX Loop.  Purchasing a few more for the balun for a T-Match is only
>> $1 more.
>>
>> DX Engineering has the 1.5" X 72" boom addition for the W5WVO design for
>> under $14.  I'll be ordering that next payday, also.
>>
>> Carl wrote:
>>> There is only about .1dB to be gained on that boom length. However the 
>>> F/R
>>> can be much improved from 18 to 28dB if noise is an issue. That boom 
>>> length
>>> is better for 4 elements at 10 dBi gain and 26 dB F/R if you dont mind a 
>>> DE
>>> impedance of around 17 Ohms which can easily be stepped up with a T 
>>> Match.
>>>
>>> In order to adapt any new design that original gamma match has to go. I 
>>> use
>>> the all metal T Match in all my designs.
>>>
>>> Unfortunately I havent added these designs to a PC file yet but can 
>>> snail
>>> mail it. This was designed about 12-13 years ago using YO, built and
>>> verified. However that HD is long since crashed and I cant find the 
>>> floppy
>>> backups.
>>>
>>> Plus I still cant get YO 6.5 functioning on a XP PC with the DOS 
>>> simulators
>>> Ive tried.
>>>
>>> Anybody have YO 7.5 they are willing to share?
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>>
>>> ----- Original Message ----- 
>>> From: "John Kemker" <john at kemker.org
>>>> I was wondering if anyone had come up with an improved layout/spacing
>>>> using the A50-5S as a basis?  I have an A50-5S, but feel that there
>>>> should be some way to improve the performance with a few
>>>> modifications/changes.  Anyone have any suggestions?  I can lengthen 
>>>> the
>>>> boom, change the lengths and spacing of the elements, etc.  I'm not
>>>> going to be able to do much in the way of modifying the gamma match, or
>>>>
>>>>
>>>> adding extra elements.
>>>>
>> -- 
>> --JohnK
>> 73 de W5NNH
>> 10X 75371/M&M 117/SMIRK 6185/Six Club 285/TRA 2499/Norcross 228 F&AM
>>
>>
>>
>>
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>>
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