Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org)
Message-ID: <200702131214070610.57DF4E04@smtp.wanadoo.fr>
In-Reply-To: <001701c74ee7$d2ba8700$0300a8c0@lark>
References: <PAEFLMFGBDKKCONLMLBIKEHICJAA.ganymede444@btopenworld.com>
 <001701c74ee7$d2ba8700$0300a8c0@lark>
Date: Tue, 13 Feb 2007 12:14:07 +0100
From: "John RABSON" <john.rabson@wanadoo.fr>
To: rsgb_lf_group@blacksheep.org
Mime-Version: 1.0
Subject: LF: 807 (was TIL Grabber back online...)
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Status: O

I believe that at Station X (aka Bletchley Park) the monitoring positions=
 used large numbers of HROs and AR88s, fed from a common aerial farm.  Some=
 kind of preamp was needed and I have been told they used several 807s.

I also came across an Old Timer who used a single 807 on CW, running 110 W=
 input.  He said "It's very simple.  You keep the volts up, the current=
 down and be careful of the screen dissipation.  Anyway, I have a large box=
 of these which I got government surplus".

73
John F5VLF

*********** REPLY SEPARATOR  ***********

On 12/02/2007 at 20:53 Alan Melia wrote:

>No No Dave lotsa volts and lotsa milliamps, Nuvistors a trifle fragile
>compared with 807s..... I believe Brian CT1DRP built one or used one for=
 an
>e-probe. Feeding can be a problem, they do have a bite !!
>
>Alan
>
>----- Original Message -----
>From: Dave G3WCB <ganymede444@btopenworld.com>
>To: <rsgb_lf_group@blacksheep.org>
>Sent: 12 February 2007 20:33
>Subject: RE: LF: Re: Re: TIL Grabber back online...
>
>
>> 807 =3D vacuum tube =3D WW2 transmitting Beam tetrode. You could try a
>Nuvistor
>> ;-)
>>
>> 73, Dave G3WCB IO91RM