Envelope-to: dave@picks.force9.co.uk
Delivery-date: Wed, 06 Jul 2005 10:11:52 +0100
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From: "Alan Melia" <Alan.Melia@btinternet.com>
To: rsgb_lf_group@blacksheep.org
References: <NKEMLGOEKANPNJOBFBAFEEJKCFAA.g4wgt@tiscali.co.uk>
Date: Tue, 5 Jul 2005 21:40:19 +0100
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Subject: LF: Re: RE: Re: RE: G0MRF 300w Tx PA mods
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Hi Gary Ah that won't give any trouble, just make sure you have enough
"headroom" for the 3 legged reggies....4v should be enough but marginal if
you have droop under load. You have nothing active in the main supply to
take exception to strange loads. I think there is an electronic fuse on Dave
G3YXM's site that might be useful.....I dont know whether you would sense a
supply current increase before the failure.
Alan


----- Original Message -----
From: "Gary - G4WGT" <g4wgt@tiscali.co.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: 05 July 2005 20:37
Subject: LF: RE: Re: RE: G0MRF 300w Tx PA mods


> "What sort of PSU is it ??"
>
> It is a simple affair using a big toriod transformer, 40V x 40V at 6.3A
> 500VA with windings in parallel smoothed by 2 x 10,000MFD 100V capacitors
> (voltage is about 45V before going to transmit state) & a smaller toroid
to
> supply about 28V DC to 24V & 12V 3 leg IC regulators within the
transmitter.
>
> I am only using the variac at present because I wanted to bring it up
gently
> until I was sure that all is well, I will need to fit some sort of soft
> start when I am happy with it & know I can run it at max volts, I can then
> remove the variac.
>
> Thanks for your feedback.
>
> Regards,
>
> Gary - G4WGT - IO83qp
>
> Web : http://myweb.tiscali.co.uk/wgtaylor
>
>
>