From: TexasRF@aol.com
Sent: Saturday, September 11, 2010 6:03 PM
To: jim.thom@telus.net ; amps@contesting.com
Subject: Re: [Amps] SHV connectors great, but where to find coax?
Hi Jim, I could not find any ratings for the P{asternak connectors. When I
received them, I was a bit dubious of them handling enough voltage.
The dielectric of the center conductor of the coax has to be left about a
quarter inch or so longer than a typical connector and it fits down into the
connector to provide the needed leakage path. I installed one connector on the
RG213/U and tested it for breakdown. I found none at 10 KV so stopped and used
the connectors.
The Pasternack's are all SHV-5 [ 5 kv rated].... including the ones they
sell, that take 213 coax. Other's sell SHV-10 and also SHV-20. [ male ends]
I have not found a source for the female chassis bulk head SHV-10/20's.
That is why I was wondering if some silicone grease globbed onto the center
pin/dielectric might be a good idea before assembly.
I researched this out really good. Dow Corning DC-4 has a LOT of electrical
applications listed..under "applications". And DC-4 has a break down of
1000 v per .001" . I was told by Ken Hirchberg at cal-av labs to use it
on the pins of all my 7-6 Din coax connectors... and also on the threads.
Other's will use DC-5 and also Dow corning ... " high vac grease" . DC-5
has NO electrical applications listed under "applications". DC-5 is only
450 volts per .001"
Dow corning ...." High vac grease has NO electrical applications listed under
"applications". It also does NOT list any V breakdown.
I believe there are now four USA stations operating EME on this band. We sure
could use some company!
I have a hard enough time on HF..never mind EME. I will defer to Lionel
Edwards for the EME stuff. [VE7BQH]..who gave a talk at our local club... back
in 1969. That guy is hard core EME.
Later... Jim VE7RF
73,
Gerald K5GW
In a message dated 9/11/2010 9:26:20 A.M. Central Daylight Time,
jim.thom@telus.net writes:
Date: Sat, 11 Sep 2010 08:35:48 EDT
From: TexasRF@aol.com
Subject: Re: [Amps] SHV connectors great, but where to find coax?
Dave and all, the last SHV connectors I purchased were from Pasterrnak, the
high priced specialist folks.
They have SHV cable and mating chassis connectors for RG213/U coax. II
wanted the security of extra voltage handling because of around 10 KV used in
a
twt power supply.
The coax connectors were about $25 and the chassis connectors were about
$15.
They worked out really well and I will never use any other type of hv
connector on future projects.
A three inch length of heat shrink was installed on the cable ends for
reinforcement and added mechanical security for the coax shields. This is a
cheap and effective way to add protection in a critical for safety location.
I have wondered if adding a dab of silicone grease to the center pin to
coax dielectric area before connector assembly might be a good idea to
eliminate air gaps and moisture traps. Any opinions on that?
73,
Gerald K5GW
## I looked up SHV on wikipedia... and it sez a SHV is only good for
3500 v rms ... so add 41% = 5 kv dc. They also say there are higher
voltage. I looked and couldn't find anything from anybody...that was more
than 5 kv. This version you found from pasternack.... other than it takes
213u size coax... does the mating female chassis connector + 213-U size
male..rated for 10kv ??
## one could also probably use use RG-393 teflon coax. It's a tiny bit
smaller than 213. [.390" vs .405"] RG-393 is solid teflon dielectric...
and is
probably overkill... but I have loads of it.
## I just may have finally found a HV connector I like... provided it handles
8 kvdc..safely. I gave up on Aldens, Millens etc. I then just hardwired
the B+
at both ends..with sta-kon crimp connectors [also soldered]... and machine
screws.
Takes awhile to get apart though.
## Is pasternack the only ones who carry RG-213 size SHV male connectors ?
Is the chassis female a regular SHV chassis connector... or a special 10 KV
rated one ??
Tnx........ Jim VE7RF
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