Message-ID: <48EB7910.2060408@dsl.pipex.com>
Date: Tue, 07 Oct 2008 15:58:24 +0100
From: Tim Hague <m0afj@dsl.pipex.com>
User-Agent: Thunderbird 2.0.0.17 (Windows/20080914)
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
References: <005901c9279c$1921d980$0201a8c0@home> <065D6E9F40984306A9A336C849B364BB@AGB>
In-Reply-To: <065D6E9F40984306A9A336C849B364BB@AGB>
Subject: Re: LF: ATU
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


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