cre8900 off frequency usb

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dt307
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cre8900 off frequency usb

Post by dt307 » 02 Aug 2017, 13:27

just had one in miles off frequency

the hidden menu adjusted to the max bf 130 and still 50hz off on usb

now the bf 240 and sounds awesome after this mod to pull the frequency a smidge

might help some one as not seen it posted and i did look around
8900mod.png
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Chanty Wrassler
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Re: cre8900 off frequency usb

Post by Chanty Wrassler » 04 Aug 2017, 11:43

More details, please. Is that a VR and what value is it?
I have exactly this problem and can't find anything useful, even though it seems to be a common enough fault on these.

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cb4ever104
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Re: cre8900 off frequency usb

Post by cb4ever104 » 04 Aug 2017, 12:53

Looks like a variable cap , but I'm sure Chris will give us the details :)
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listner132
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Re: cre8900 off frequency usb

Post by listner132 » 04 Aug 2017, 19:17

dt307 wrote:just had one in miles off frequency

the hidden menu adjusted to the max bf 130 and still 50hz off on usb

now the bf 240 and sounds awesome after this mod to pull the frequency a smidge

might help some one as not seen it posted and i did look around
8900mod.png
see here viewtopic.php?f=53&t=39710&p=346744#p346744 chris..
much thes same thing but with anyton at5555

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Re: cre8900 off frequency usb

Post by Chanty Wrassler » 04 Aug 2017, 21:32

That is very, very useful information. Thank you.

I also found this on the wayback machine - unfortunately, the pics are gone, but the description is reasonably good.
https://web.archive.org/web/20111007065 ... oscadj.htm

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dt307
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Re: cre8900 off frequency usb

Post by dt307 » 05 Aug 2017, 10:53

It's a variable capacitor but

I tried a 2pf disk hq cap and that was too much
I didn't have a lower cap to hand and thought I try a trimmer i had handy .

The trimmer is set to it's lowest value some where between 0-2pf your milage may vary
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Chanty Wrassler
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Re: cre8900 off frequency usb

Post by Chanty Wrassler » 05 Aug 2017, 11:06

Excellent, thank you.
That gives me something to work with. I'll leave it for now, as it seems to be stable at -1kHz off, which although a nuisance is easily taken into account and the channel changer retains the offset when changing, so makes life easier.
There's a rig doctor with some good kit up the road a bit from me, and he's got a good rep (not merely a twiddler, by all accounts) and the facility to do proper setups, which I don't have. I'll be able to hand him the set and the info and let him take it from there.
Many thanks to all.

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dt307
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Re: cre8900 off frequency usb

Post by dt307 » 06 Aug 2017, 09:14

Mine wasn't that far off it was 500hz
1khz is a bit more .
I found try to get the usb on frequency with the combo of cap and bf 200-300 .
If you add a cap of to big a value your bf will be 300+ and that will make your lsb go bad.
Use the min amount of capacitance neededthen set usb bf,
Set lsb bf
Then am fm if your keen
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“I fear the day that technology will surpass our human interaction. The world will have a generation of idiots.”
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