Hi Joe in theory 50kV will need about an inch ....25mms but this is always
a
try it an see thing in my mind. I reckon it "non-linear" on you strike an
arc you can increse the gap a lot before it goes out....so if you can
prevent an arc starting?? It is a strage situation...... maybe you do need
a
big gap at that voltage....a solenoid operated short?? A door closer
solenoid or a rotary one should have enough throw, and you can always use
some mechanical "amplification" for a bigger gap ??
Alan
----- Original Message -----
From: "Graham" <[email protected]>
To: <[email protected]>
Sent: Tuesday, October 11, 2011 12:17 PM
Subject: Re: LF: VX9MRC QRV 507.77 kHz/ Arcing relays &c.
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: <[email protected]>
Sent: Tuesday, October 11, 2011 2:11 AM
To: <[email protected]>
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: <[email protected]>
>> To: <[email protected]>
>> 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 [email protected]:
>>>>> 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
>
>
