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Old February 22nd 05, 04:43 PM
bpnjensen
 
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Weren't you experimenting with crystal radios a year or two ago?
Generally,
repair is easier than homebrew.


Yes, but a crystal radio is far less involed than something you plug
in! :-)

Nearly all single conversion superhets align using the same simple
procedures. I think the DX-160 service manual is online, and the ARRL


handbooks have some good straightforward alignment instructions.


You can even do excellent alignments without a signal generator, if

you have
digital readout receiver to read the radio's local oscillator

frequency.

However, the radio may be aligned about as well as it can be.

Generally,
the dial readout is exactly correct at two or three points on the

dial, at
best. There are usually areas in which the dial readout doesn't

perfectly
track with the received frequency probably because the tuning

capacitor/
coils don't exactly match the prototype they developed the original

dial
from.


Anyway, if you want to give it a try, I'm sure you can get some help

here.

Frank Dresser


THEN...

looking at the schematic, it's got a ceramic/xtal/mechanical(?)

filter
for the first IF, so you can't really screw up the tracking by shifting

the IF like you could with an all LC tuned IF.

What I'd look for first is to see if the dial pointers haven't shifted
on the cord(s).

Mark Zenier Washington State resident

Mark and Frank - the frequency aligns correctly near the lower end of
each band - for example, on the 4-12 MHz band, WWV shows up at
virtually dead-on 5 MHz. At the upper end of the band, however, WWV is
off by *about* .6 MHz from 10 MHZ (depending on what the radio ate for
breakfast), and things are a bit worse on signals near 12 MHz. The
same is proportionally true for each of the other bands.

The bandspread dial, when used, is off by varying degrees from one end
to the other, ranging from nil to about 15 or 20 khz.

I have some instructions for fine tuning these ranges using the
band-specific coils within, but thus far I simply haven't had the nerve
to touch them. Someday I may, but I am content for now to be primarily
a listener rather than a tinkerer.

Bruce Jensen