LO Filter test

Discussion about this major DATV Project. See also https://wiki.batc.tv/The_Portsdown_Transmitter
G3UEQ
Posts: 78
Joined: Sun Jul 26, 2015 10:28 am

Re: LO Filter test

Post by G3UEQ » Fri Nov 30, 2018 11:03 am

That's a shame, something died in o/p stage or an enable function for that chip.
Yes, I use flux pen and good solder wick now, I do have a small hot plate, but not plucked up courage to use that. Have dropped hint for a re-flow station for Xmas!, and yes, I will continuity check on my second filter build as you have done.

Andy

G3UEQ
Posts: 78
Joined: Sun Jul 26, 2015 10:28 am

Re: LO Filter test

Post by G3UEQ » Fri Nov 30, 2018 3:01 pm

G3UEQ wrote:
Thu Nov 29, 2018 11:04 am
Dave
It looks like duff filter board, 71MHz o/p has now died, 2m and 1.3GHz o/ps reasonably OK, lower o/p on 437MHz. Bypassing the filter showed no o/p at 42.6MHz!
So will order new PCB and set of parts from Digikey. That was my first go at SMD and not pretty so maybe s/c somewhere. RF switch was quite neat attempt.

Cheers
Andy
Dave, not sure if you posted replacement board, but whoever it was arrived this morning many many thanks!

G8GKQ
Site Admin
Posts: 976
Joined: Sun Mar 22, 2009 1:21 pm

Re: LO Filter test

Post by G8GKQ » Fri Nov 30, 2018 3:23 pm

Andy

I can't take the credit for that - it was Noel.

Dave

G3UEQ
Posts: 78
Joined: Sun Jul 26, 2015 10:28 am

Re: LO Filter test

Post by G3UEQ » Fri Nov 30, 2018 8:00 pm

Thanks Dave!
And thanks Noel!

Andy

g8gtz
Posts: 989
Joined: Wed Apr 07, 2010 6:26 pm

Re: LO Filter test

Post by g8gtz » Fri Nov 30, 2018 8:08 pm

:-)

G3UEQ
Posts: 78
Joined: Sun Jul 26, 2015 10:28 am

Re: LO Filter test

Post by G3UEQ » Mon Dec 03, 2018 3:03 pm

Parts arrived from Digikey, now to build replacement LO filter and repair 1st, might be a spare one later"

Andy

G3UEQ
Posts: 78
Joined: Sun Jul 26, 2015 10:28 am

Re: LO Filter test

Post by G3UEQ » Tue Dec 04, 2018 7:54 pm

New LO filter fitted and working well, get video now on all bands. Appears to be bit of overdrive in IQ modulator, going to change R24 a,b,c and d to latest specification,
Andy

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