Message-ID: <AC8ED70D8DEF4AE48EB2344F423581FE@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Date: Sun, 28 Mar 2010 19:49:16 +0100
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Subject: Fw: LF: ATU
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Follow  on from 2008  ... was it that  long ago  ?

>> parallel , Worked well on rx and would handle up to  25 watts on tx
>> before the plates flashed over ! but easy to  make easy to tune ,

Re hashing the  Cap  so  there  was   2 sets  of  plates in parallel  and 
then in series  with the  other  2 plates .. doubled the gaps , .useing the 
shaft as the  coupling  link  .. we  where  pushing the  envelope  in those 
days ...

G ..



--------------------------------------------------
From: "Tim Hague" <m0afj@dsl.pipex.com>
Sent: Tuesday, October 07, 2008 3:58 PM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: ATU

>
> Graham wrote:
>> Simple tuner
>>
>> If it works on top band, then it will work on 500 (with a bit more C)
>> .. this is a simple parallel tuner , with a WW2  ex usa surplus
>> transmitter coil, and a  2000 pf capacitor 4 x 250pf  wired in
>> parallel , Worked well on rx and would handle up to  25 watts on tx
>> before the plates flashed over ! but easy to  make easy to tune ,
>> rx/tx tapped 2 turns from the bottom and the  Ae direct to  the top
>> (the knob is from the B set .. ws19)
>>
>> http://uk500khz.googlegroups.com/web/Parallel+ATU?gda=AekYBT4AAAD_AR9CZEwmTaUFcglf9MHbexqv2sBQZsAxVg3n14BVSpRSVTbPEv7Iv69fZDO_RFvjsKXVs-X7bdXZc5buSfmx
>>
>> G ..
>>
>>
>>
>> *From:* Chris <mailto:c.ashby435@btinternet.com>
>> *Sent:* Monday, October 06, 2008 11:12 AM
>> *To:* RSGB lf Group <mailto:rsgb_lf_group@blacksheep.org>
>> *Subject:* LF: ATU
>>
>> Hello Tim,
>> My ATU is really a large matching coil. It consists of 130 turns of
>> insulated solid copper wire on an 11.5cm dia. cardboard former (carpet
>> roll centre) tapped every ten turns (course tuning) in series with a
>> coil of 22 turns of 18 swg enam. copper wire, 7cm long, 6cm dia. and
>> tapped every two turns (fine tuning). I find this will resonate my
>> 124' wire from Medium Wave, through 500kHz, to all the NDBs.
>> I built this so I could use it for TX one day. If you are going for RX
>> only, take a look at 'LF Today', second edition, p14 and 15. This is
>> my next project, got all the parts, building this week.
>> All the best.
>> Vy 73,
>> Chris, G4AYT, Whitstable, Kent.
>>
>> ------------------------------------------------------------------------
>>
>> No virus found in this incoming message.
>> Checked by AVG - http://www.avg.com
>> Version: 8.0.173 / Virus Database: 270.7.6/1709 - Release Date:
>> 10/5/2008 09:20
>
>
> Thanks Graham, I've actually got a full set of these coils which came
> from Hanslope Park, I wonder what they were used on.
> Anyway I've found a suitable cap from a high power MF Tx on another site
> so when that arrives I'll be well away. I understand its possible to get
> some power
> out of my 756PRO3 so then I'll have a look at that next..
>
> Tim M0AFJ
>
>



>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.173 / Virus Database: 270.7.6/1712 - Release Date: 10/7/2008 
> 09:41
>