Today (and yesterday) I opened the TR-4 filter and replaced all the
crystals with unselected DigiKey 50cent crystals. Now the dead filter
does pass a signal but is not useful. Good learning fun though and I
documented it some on the blog at http://pgerhardt.blogspot.com
Ck it out if you want to
Thanks Garey and Gary for your inputs.
I put my points from my rather crude measurements and actually got a
somewhat meaningful curve. Next I am going to attempt to open the
'Bad Non X filter' that is marked 2100 L.
OK the L IS for LSB but on 40 there IS inversion so the 2100 U(SB)
filter is
I tried a crude measurement on the working 'X' filter marked
SSB 9M 2100 U
Why does the 'U' filter peak on the low side of the Center Freq?
The 'non X' filter will not pass a signal btw it is marked 2100 L
If the 'U' and 'L' are for USB and LSB I am guessing that the USB and
LSB are only
Paul -
I get myself confused every time I try to explain this... Please delete previous message before
I get you confused too!!!
** REVISED
Because of the mixing scheme used in the TR-4, the filters are NOT really USB and LSB,
Paul
I have opened several of the filters using a very hot iron and lots of
solder wick. I have about 5 or 6 of them. Inside you will find eight
crystals and a few disk capacitors. I had planned on trying to take a few
bad ones and make a good filter but have yet to try. I suppose a torch
Paul -
I get myself confused every time I try to explain this... I obviously should NOT try this after
lunch At least I got the first two sentences correct! :-)
Because of the mixing scheme used in the TR-4, the filters are NOT really USB and LSB, but #1 and
#2. I know this is
I have a TR-4 that only works on the X sideband. This unit has blue
filters but they do not seem to be Tyco filters mine are made by
TEDxxx (cant quite read) Crystal Lab in Ohio they are blue and are
numbers 2100U and 2100L. Would a 'Tyco' filter work as a sub?
Paul Gerhardt
K3PG
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