----- Original Message -----
From: "Rob Atkinson, K5UJ" <k5uj@hotmail.com>
To: <km1h@jeremy.mv.com>; <towertalk@contesting.com>
Sent: Monday, August 20, 2007 7:24 PM
Subject: Re: [TowerTalk] Hygain pushup masts for 80m verticals?
>I bought two 50 foot steel pushups from an outfit in Memphis 2 years ago
>when I was down there--they were the last ones they had. I got them for
>$90 each--they took $30 off to get rid of them. Last year, Burghardt had
>rohn H50s in stock. I don't know how many. I did not pursue it with them
>because the cost of getting them here made getting them pointless. If you
>get them shipped, they usually wind up on a truck loose (even collapsed
>they are too long for UPS) and they wind up getting too banged up to be
>useable. I guess they are getting hard to get because the demand is no
>longer there. Folks in fringe TV coverage areas who used to get these 50
>footers for TV now have cable.
>
> <<If using a steel mast then first calculate the RF resistance at the
> frequency of operation. The RF integrity at the various junctions is also
> far from ideal.>>
>
> Correct. When you put one up as an antenna you have to deal with that.
>
>
> <<<Aluminum is still the best for a radiator>>>
>
> I'll alert the broadcast industry.
Please do the next time you see one using a thin wall steel mast with less
than perfect plating that may quickly rust in some enviroments.
>
> <<<and with several others helping on the guys that HyGain mast should go
> up OK. They wouldnt be selling them if they didnt work.>>>
>
> Hygain is owned by MFJ now. Oh, it will work. For awhile. I'm trying to
> help him put up something that lasts.
So is Ameritron and their amps pretty much own the market.
Here's a few others for you:
> Isotron, GAP, EH antenna, Gotham....they work too (sort of).
>
> <<<One way to secure the sections is to drill a small hole thru the
> louvered part of the hose clamp into the mast and secure with a SS #6 self
> tapping screw. Dont use a screwdriver to tighten the clamps, a socket on a
> ratchet wrench gives more torque. Assemble the sections with a small
> amount of Penetrox or similar to protect against corrosion.>>>
>
> I agree except for the socket wrench part. Great way to destroy a cheap
> hose clamp.
Its also a great way to get a secure clamp on the element, a screwdriver is
only good to quickly get it tight enough to let the wrench finish the job.
It doesnt take a genius to get the feel for the torue required. If the clamp
is cheap then get a good Ideal one at an auto parts store; make sure it is
ALL stainless, not just the band. Ive used clamps on yagis from 40 to 6M and
never had a quality one fail.
Carl
KM1H
>
> 73,
>
> rob / k5uj
>
>
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