Pete Smith wrote:
> Isn't schedule 80 water pipe?
Rarely do you find water pipe that heavy. It's usually schedule 40, but
it does come that way.
Structural steel tube is also available in schedule 40 and 80.
73
Roger (K8RI)
> And if so, aren't you inviting a bent
> mast by trying to put a 2-element 40m yagi 10 or more feet above the
> tower top?
>
> 73, Pete N4ZR
> Visit the Contesting Compendium at http://wiki.contesting.com
> The World Contest Station Database, updated daily at www.conteststations.com
> The Reverse Beacon Network at http://reversebeacon.net
>
>
> On 1/26/2010 8:31 PM, Jon Casamajor wrote:
>
>> Hi Rick,
>>
>>
>>
>> You wrote:
>>
>>
>>
>> I have a TH6 right at the top of my tower and a Cushcraft A3WS about 9 feet
>> above that. I have a serious tower and rotator and am going to add a 2
>> element 40 meter yagi this Fall. Can someone give me an idea of spacing
>> requirements between the three antennas? I have a 20 foot mast, 10 feet of
>> which is currently inside the tower. I plan to move up the rotator shelf.
>> Right now the mast only sticks up 10 feet. It's 1/4 wall Schedule 80. I'd
>> rather not side mount the A3WS lower down the tower as a local suggested.
>> Thanks for any guidance. Rick VE9HF
>>
>>
>>
>> You don't have much mast to work with Rick. For 15 years I had a KT34-XA
>> mounted just above the thrust bearing and 10 feet above that and 90 deg out
>> of phase with the XA I had a 402-CD which was at about 90 feet AGL. That
>> combo worked super and having 2 el on 40 was a lot of fun and helped get me
>> 5BDXCC.
>>
>> I guess my real question is how high are you going to be able to put the 2
>> el 40? If you can get it up to 80' or so, it will start to play pretty well
>> probably assuming you can get some separation from the TH6 but your
>> available mast will make that a challenge probably. My gut feeling is that
>> with only 10' of mast or so to work with you won't be able to get either
>> antenna to work very well. You need more mast IMO.
>>
>> I still have the 402-CD up 10' above SteppIR but have some VHF/UHF below and
>> above the 402-CD and it still kicks butt. I am taking it down this spring to
>> make more room for some additional VHF stuff. I run the 402-CD in phase with
>> the SteppIR with no problems but, and it's a big but, I can tune out a lot
>> of the interaction with the SteppIR on 15m. It's awfully nice to be able
>> to point the whole stack in the proper direction.
>>
>> There is a picture of my current stack on QRZ. Buy some more mast, assuming
>> your tower can handle it and you will be happier with more separation than
>> you are planning.
>>
>>
>>
>>
>>
>>
>>
>> 73, Jon
>>
>> K6EL
>>
>>
>>
>> _______________________________________________
>>
>>
>>
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>>
>>
>>
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