[UK-CONTEST] A Weird Dressler D 200 S Linear Amp Problem

[Nigel Newby]

Rule one. If it don't work HIT IT
> Nubsey G0VDZ
----- Original Message ----- 
From: "Will M0GYZ" <m0gyz at gb3hp.co.uk>
To: <vhfcontesting at contesting.com>; <uk-contest at contesting.com>
Sent: Wednesday, March 17, 2010 11:23 PM
Subject: [UK-CONTEST] A Weird Dressler D 200 S Linear Amp Problem


> Hi All
>
> Thanks for all the help
>
> I opened the case today to find to a little safety mechanism (which is
> connected by 2 red leads going to somewhere underneath to the right of
> the fan) which pushes down when the case is on otherwise the linear does
> not transmit so after pushing it down a couple of times seemed to fix it
> I must have been using it for at least 3 hours this evening without a
> hitch untill i moved to a more perminant location and then it stopped
> working again and when i pushed down the mechanism again with the linear
> in standby it all turned off and it turned out I blew a fuse in the
> mains plug which was only 5 amps.
>
> At least I think ive found the problem though which is step 1
> now for the solution
>
> Here is the Manuel for it
> http://www.qth.at/oe1cwj/Dressler%20Manual%20D70_eng.pdf
>
> and here is a better pic of the inside so you can see what i'm talking
> about
>
> http://img225.imageshack.us/img225/4453/dressler.jpg
>
> As you can see there is a yellow wheel like thing to the right of the
> fan with 2 red leads coming off it
> thats the safety mechanism
>
> Thanks
> Will M0GYZ
>
>
>
>
>
>
> On 17/03/2010 18:05, Paul Kiesel wrote:
>> Hi Will,
>>
>> Check that the solder on the output coax connector  is not open. Some
>> brick amplifiers will "bend" when being moved around. Very often the
>> solder will fracture where the output lead is soldered to the
>> connector. Look closely as it is hard to see. Good luck!
>>
>> 73,
>> Paul, K7CW
>>
>>
>> ------------------------------------------------------------------------
>> *From:* Will M0GYZ <m0gyz at gb3hp.com>
>> *To:* vhfcontesting at contesting.com
>> *Cc:* uk-contest at contesting.com
>> *Sent:* Tue, March 16, 2010 12:54:46 PM
>> *Subject:* [VHFcontesting] A Weird Dressler D 200 S Linear Amp Problem
>>
>> Hi All
>>
>> Got a weird one for you.
>>
>> I have Dressler D200S VHF Linear Amp which was given to me for 
>> contesting.
>> There has always been a strange problem which i originally thought was a
>> sticky relay
>> However after a while of looking at it. Its as if the amp wont Transmit
>> without it being on a really flat surface which caused problems for me
>> at the recent 144/432mhz contest
>> I can't figure out why it would require such a dead flat surface before
>> the needle moves and im putting power out.
>>
>> It was working ok apart from this at home as i was putting out 120w with
>> 5w drive provided I found the right spot for it but when i took it out
>> to the contest it just didn't want to Transmit at all and when it did
>> the power just decreased over 3-10 seconds and I couldn't get 120w out
>> of it max.
>>
>> My thoughts are thats it might be a dry joint but the guy who had it
>> before me didn't ever report it had a problem but unforuntly he died a
>> couple of years ago.
>> So it only Transmits when its in a spot it likes after moving around my
>> windowsill
>>
>> So any thoughts  ?
>>
>> Thanks
>> Will M0GYZ
>> _______________________________________________
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>>
>
>
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