Joe..
There are some 'good' rf relays at :-
http://www.surplussales.com/Relays/rfopen.html
Ive used the small open frame one's for some time on the HF bands
may be a couple of the 6 Kv open frame in series would work ?
G..
--------------------------------------------------
From: <jcraig@mun.ca>
Sent: Tuesday, October 11, 2011 2:11 AM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c.
Hi Alan, Group.
Thank-you for the reply. Multiple contacts in series were considered...
but the gap has to
increase by orders magnitude! How much gap will I need for 50 kV?
Your spiral pie story was most enlightening. My pies are ~35 turns of
4mm litz about 37 cm diameter with L=0.24 mH. A stack of 4 yields
3mH. Each pie has ~23 metres of litz. Do you think this is will give
the most L for the least length of litz?
VX9MRC is still sending the 8 WPM beacon as yours truly looks at a fried
relay...
Cheers
Joe
On Tue, 11 Oct 2011, Alan Melia wrote:
Hi Joe, why not stick two sets of normal contacts in series....doubles
the
gap :-))
Alan
----- Original Message -----
From: <jcraig@mun.ca>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, October 10, 2011 11:54 PM
Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c.
Hello Hartmut, Group.
Good to hear from you again, Hartmut. Thank-you for the report.
The beacon is on again, but there was some trouble: to use the tower
on 160m the 500 kHz tuning coil (0.2 mH) is shorted by a relay. The
N.O. contacts on this relay arced over. Perhaps a high voltage (vacuum)
relay would help?
This problem will be much worse on 137.777 kHz with the higher voltage.
I have some spiral wound 4mm (Decca) litz to make up the 3 mH for that
project. (The spiral winding was inspired by G3NYK's experiments with
tuning coils on his web page.)
73
Joe
On Mon, 10 Oct 2011, Hartmut Wolff wrote:
Am 2011-10-09 23:50, wrote jcraig@mun.ca:
Dear Group,
Reports on the 8 WPM CW beacon will be appreciated!
73
Joe VO1NA
Attached a screenshot of the 8wpm signal. The signal came up at about
23:20
and faded out at about 7:35. The strongest part was between 04:00-06:00
UTC
--
73
Hartmut
www.h-wolff.de
Locator: JO52hp
This electronic communication is governed by the terms and conditions at
http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php
This electronic communication is governed by the terms and conditions at
http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php
|
