When I was selling high power parts in the 80's and 90's the Alden's far
outsold the Millen to hams and commercial customers. At first just plugs and
sockets were available that would take up to #18 20kv wire. Then they
switched to a socket with a 24" #22 molded wire which was OK for most as
the plug could still take up to #18. They had a bigger set at higher voltage
but there was a huge price jump and I only sold those on special order.
Ive a small box in the basement with arced Millens returned by customers.
Examination shows that no flights of fancy with polished metal would have
prevented failure. They were simply defective and dangerous, especially for
4-1000A builders. I often show these to visitors and take them to hamfests.
Perhaps the manufacturing process had problems as there were 2-3 changes of
ownership at the time.
My Millen sales were often replacements to hams whose old ones had cracked
or arced over decades even at modest voltages so it wasnt entirely a new
phenonoma.
I still wont use them at any more than half their ratings; Ive enough safe
alternatives here to choose from for higher voltages.
Carl
KM1H
----- Original Message -----
From: "Jim Thomson" <Jim.thom@telus.net>
To: <Amps@contesting.com>
Sent: Wednesday, January 13, 2010 1:24 AM
Subject: [Amps] Which HV connector to use.
>
> Date: Tue, 12 Jan 2010 20:20:34 -0500
> From: "David H Craig" <davidhcraig@verizon.net>
> Subject: Re: [Amps] which HV connector to use?
>
> C connector, HN, or even RG214 with connectors will work fine
> (commercial TX often use RG214 for 8kv in the States). Otherwise buy a
> Millen connector & use HV cable- about $20-35 US on Ebay, but cheaper at
> hamfests. If you use one of the RF coax connectors, just make damn sure
> you
> mark it as such in the event an unknowledgeable person decides it it an RF
> line...
>
> See you soon on 50 MHz TEP!
>
> 73 Dave N3DB
>
> ## Why 214 ? It has a double braid vs single braid of 213 u. 214
> is bigger OD, and harder to install a pl-259 on.
> Are these broadcast TX using UHF pl-259 /so-239 pairs.. or something
> else??
>
> ## rauch said he hi pot tested RG-58-u.. and could not draw any leakage
> current... even with 15 kv. [ limit of his hi -pot]
> Measures hi pot limit is 30 kv... and again, no leakage current with
> RG-58-u
>
> ## Although they rate 393 Teflon coax at 7 kv.... if u actually hi-pot
> tested it... I bet it would take 80 kv to draw any leakage current.
>
> ## I'm not worried abt using coax for B+.... but using coax connector's
> on each end. I don't think I would want to trust a UHF pair,
> even with Teflon connectors. The B+ would just blow right up the crack,
> where the 2 x Teflon surfaces mate... an/or... it would arc on the
> backside[inside]
> of chassis, on the SO239.
>
> ## perhaps using plane 213-U.... but with the center conductor + braid
> separated with a big crotch, and stakon crimp connectors would work?
> then machine screw down both the braid and center conductor... and each
> end of the cable. Electrical box's now have adjustable diameter strain
> relief's.
> These things are slick... just twist em, and they cinch down on the cable,
> and pinch it tight.
>
> ## I'm not impressed with the Alden HV connector's either. No pos lock
> on em. They come with HV cables attached on both halves.. and usually too
> short.
>
> later........ Jim VE7RF
>
> _______________________________________________
> Amps mailing list
> Amps@contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|