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RE: [TheWhittonARG] bitx

think we need a few tuning caps 2 or 3
also thet will all need 3 x 33pf for the banpass filter
as we used 47pf.mike found that out and changed them
Colin

 

To: TheWhittonARG@...
From: michael@...
Date: Thu, 16 Jul 2009 08:11:32 +0100
Subject: Re: [TheWhittonARG] bitx

 
Hi

I have some heat sink compound.

I did not test the BP filter. Will try it on mine.

On Mikes board the TX is not working so I went back to the start of the TX chain which is when I noticed the mic amp was not working, not long after that Mike had to leave for home guard duties.

There is a big difference in ripple characteristics between TX and RX directions in the crystal filter, but I think finding the cause of the insertion loss may be more productive than fiddling with the capacitors. Unless 17db is normally to be expected, that is worth checking out in the literature.

Mikes enclosure has plenty of space to work in, but even then we were not able to do much with the board mounted, so it all needed to be dismantled. It will be best to get the boards tested before people start to mount into hardware.

I am sending off an order to Rapid if anybody needs anything.



Michael




On 15 Jul 2009, at 22:46, Colin Peters wrote:

Found some heatsinks at last weeks rally
got a good deal on them.

Just need to drill a hole for the bolt, anyone got heatsink compound?

1uf cap works well on mic, sould of been one built in.

Did you get time to test bandpass filter?

Colin






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Thu Jul 16, 2009 11:47 am

m0dmj
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Message #182 of 299 |
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Found some heatsinks at last weeks rally got a good deal on them. Just need to drill a hole for the bolt, anyone got heatsink compound? 1uf cap works well on...
Colin Peters
m0dmj
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Jul 15, 2009
9:47 pm

In a message dated 15/07/2009 21:47:49 GMT Standard Time, m0dmj@... writes: Found some heatsinks at last weeks rally got a good deal on them. Just...
g0mrf@...
c56dx
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Jul 15, 2009
10:53 pm

HI David OK, I will have a look for some low pf trimmers unless you have any suitable already Can your LC meter get down as far as say 20pf? Michael...
g3woe
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Jul 16, 2009
7:58 am

Hi I have some heat sink compound. I did not test the BP filter. Will try it on mine. On Mikes board the TX is not working so I went back to the start of the...
g3woe
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Jul 16, 2009
7:11 am

think we need a few tuning caps 2 or 3 also thet will all need 3 x 33pf for the banpass filter as we used 47pf.mike found that out and changed them Colin To:...
Colin Peters
m0dmj
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Jul 16, 2009
11:49 am

In a message dated 16/07/2009 07:58:52 GMT Standard Time, michael@... writes: HI David OK, I will have a look for some low pf trimmers unless you have...
g0mrf@...
c56dx
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Jul 16, 2009
6:25 pm
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