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Message-ID: <010401c64b94$c5c89de0$7900a8c0@athlon1200>
From: "Dave Brown" <tractorb@ihug.co.nz>
To: <rsgb_lf_group@blacksheep.org>
References: <003501c64b80$6cf488a0$0400a8c0@AUG2004>
Date: Mon, 20 Mar 2006 08:36:16 +1200
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Subject: LF: Re: Low power Tx
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Any chance of seeing a cct of this, Walter?
 Info re xfmrs used would be particularly interesting-just to see how 
they compare to 'local' designs.
73
 Dave, ZL3FJ (who has several tube/valve LF txs!)


----- Original Message ----- 
From: "Walter Blanchard" <blanch@pncl.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Monday, March 20, 2006 6:10 AM
Subject: LF: Low power Tx


I found a Decca Aerial Testing Signal Generator Type 1615 at a junk 
sale a few months ago. It's basically a xtal osc/driver/PA transmitter 
for LF (Decca freqs 70-127 kHz). Very easily converted for 136 because 
the o/p transformer is wide-band enough to cover 136 and needs no 
modifications. Plug about 100 mW 136 kHz RF into a xtal socket and it 
will give out 20-25w RF into 72 ohms (PA is 2x807's). My old Marconi 
2019 SG was quite adequate as signal source. Quite a lot were made so 
there may be a few more appearing round the junk sales and if you see 
one it's well worth �5 of anyone's money!

Walter G3JKV.


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