[UK-CONTEST] Fw: HF Beam/WARC dipole on same mast

[G3SJJ]

An interesting discussion as I have enough tubing and a center insulator 
to make a 17m dipole, and with a couple of Cushcraft traps from W&S 
could turn it into a 17/12m dipole. A 30m wire delta loop works well so 
I don't need anything else for that band.

The 12ft stub mast supports my 160m dipole so I wouldn't want to go too 
high up the stub mast. I did wonder about mounting it on the boom, 
somewhere between the A4S driven element and the 10m reflector.

I was thinking of assembling the 17m dipole up on a 20ft scaffold pole 
to take some measurements first, and then re-measure when it is 
installed on the boom or stub mast. Likewise I will carefully note swr / 
impedance readings on the A4S before and after installation. Should have 
done this in warmer wx, but then antenna work isn't as interesting 
without frost, wind, rain etc!!

A friend of mine G3VMK has modeled and built 2 element monobanders for 
12 & 17m and installed them on the same boom as his A3S without any 
problems. I'll try and get some details from him.

Chris G3SJJ



G3SXW wrote:
>> Ian,
>> My WARC dipole is parallel with the elements of the tribander. Originally 
>> it was parallel with the boom - no discernible inter-action either way. 
>> But it is about six feet above the KT34A. Your '2 or 3 feet' sounds a bit 
>> close for comfort. Maybe use a longer stub-mast?
>> If it's parallel with the boom it's a pain to always add/deduct 90 degrees 
>> in your head !
>> Good luck - 73 de Roger/G3SXW.
>>
>>
>> ----- Original Message ----- 
>> From: "Ian Fugler G4IIY" <zen90387 at zen.co.uk>
>> To: "UK Contest Reflector" <uk-contest at contesting.com>
>> Sent: Sunday, November 05, 2006 9:35 AM
>> Subject: [UK-CONTEST] HF Beam/WARC dipole on same mast
>>
>>     
>>> I am seeking some advice, please.
>>>
>>> I have bought a rotatable dipole for 30/17/12m.  It is about 11m long.  I 
>>> plan to mount it on the same stubmast as my HF beam (Cushcraft A3S) 
>>> (separate feeders, of course).  It would only be about 2 or 3 feet below 
>>> the A3S.
>>>
>>> Do I mount the dipole parallel with the A3S boom or parallel with the 
>>> A3S' elements?  Parallel with the boom would be a nuisance, as the dipole 
>>> is longer than the boom.  But, being parallel with the boom, there should 
>>> presumably be less inter-action between the two.
>>>
>>> I am sure that others have done this.  I would welcome any thoughts, 
>>> please.
>>>
>>> Thanks, Ian G4IIY
>>>