I need a cheap and simple analog receiver for some experiments I'm
doing and the old Realistic DX-100 will seemingly fit the bill as long
as it's reasonably drift stable over a few minutes (+/- 150 Hz or so).
What is the dial drive mechanism (knob to varicap) and the resolution
of the fine tuning. It will be used in the CW mode. Any pro and con
comments will be appreciated.

Thanks,

Frank

"Frank" wrote in message
...
I need a cheap and simple analog receiver for some experiments I'm
doing and the old Realistic DX-100 will seemingly fit the bill as long
as it's reasonably drift stable over a few minutes (+/- 150 Hz or so).


My DX 100 has a huge warm up drift. It will easily drift 5kc on the top
of the AM BC band in the first half hour or so, more drift on the higher
bands. It's better after the warm up. I can listen to SSB without
riding the tuning, but it never really stops drifting. It might be
something like 150 Hz over a few minutes, or a litte better.


What is the dial drive mechanism (knob to varicap) and the resolution
of the fine tuning.

Knob to indicator drum to a dragging plastic dielectric variable
capacitor is good old dial cord. Although the original cord seems kinda
slick and can slip.

The fine tuning control is a simple pot. The resolution is arbitrary.
It's marked off 100 - 0 - 100 with a number indication every twenty.
Twenty what? I dunno. It takes six indicator lines to go from one
twenty whatever to the next twenty whatever. The fine tuning knob is so
thin, it's almost useless.

If you start at 3.9 MHz with the fine tuning control at 0 turning it
fully clockwise (100) brings the frequency to 3.942 MHz . Turning the
fine tuning control from the same zero counterclockwise brings the
frequency from 3.9 to 3.865.

It's 7.231(100cw) - 7.2(0) - 7164(100ccw)

I checked these frequencies listening to the local oscillator radiation
with my DX 440. I assumed the IF frequency is 455 kHz.

It seems as if the fine tuning control tunes only the oscillator, and
not the antenna stage.


It will be used in the CW mode. Any pro and con
comments will be appreciated.

Thanks,

Frank

Are you going to make a huff 'n puff oscillator stabilizer? That seem
like a useful mod.

Woven cover fishing line might make a good dial cord replacement, if
needed. I have some real fiberglass core dial cord, but it's too thick
for this radio. I'd avoid the nylon stuff.

I don't like the tuning feel of the DX 100. A small knob and it has
alot of rubbery backlash. I was thinking what a nice radio it would be
if it had a air dielectric cap with a real bandspread. It might even
drift less.

Frank Dresser

I need a cheap and simple analog receiver for some experiments I'm
doing and the old Realistic DX-100 will seemingly fit the bill as long
as it's reasonably drift stable over a few minutes (+/- 150 Hz or so).

That was my first 'radio'.....actually I had two and swapped one with someone
that used to post in this group (DXZoner.)

The one I have is in *mint* condition with papers and box, it does have a
drift, but after it's been on a while it's fine.

I haven't fired mine up in over a year, might be time to break it out. ;-)
~*Monitoring The Airwaves*~
*GO BEARCATS*
~Hammarlund HQ 129X Heathkit Q Multiplier~
Hammarlund HQ 140X
Multiple GE P-780

I haven't fired mine up in over a year, might be time to break it out. ;-)

Try my new sig here :-) I'd like to list the antenna and accesories but would
that be overkill. {?}

~*~*Monitoring The AirWaves~*~
*****GO BEARCATS*****
Hammarlund HQ129X /Heathkit Q Multiplier
Hammarlund HQ140X
Multiple GE P-780's(GREAT BCB Radios)
RCA Victor *Strato- World*
RCA Victor RJC77W-K(Walnut Grain)
1942 Zenith Wane Magnet 6G 601M
Cathedral/ Ross#2311/RhapsodyMultiBand
DX100/394/398/399/402
OMGS Transistor Eight/Realistic 12-1451
Henry Kloss Model One/Bell+Howell
~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*

Try my new sig here :-) I'd like to list the antenna and accesories but
would
that be overkill. {?}

LOL You remind me of that guy on TV the other night who had 2,000 golf clubs.

Bill,K5BY

LOL You remind me of that guy on TV the other night who had 2,000 golf clubs.

My Hammarlunds and the DX398 and the GE P-780's are the ones I use the most.

I get in my moods, then fire up the RCA Victor...lol. Then one week, the 394.
Once I get that modded out along with the 398, they'll be super. It's a great
hobby. :-)