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Hello all,
Sorry to say but for the moment I decided to stop
my building
activeties for the 136kHz transmitter.
Right from the start I faced only problems in
getting things
working, and I just do not have the time to spend
days on
testing, trying doing things over and over and in
another way etc.
To give you some examples from problems I ran
into:
No suitable X-tals to build VXO 's or something
with an divider, so I decided
to build an VFO on 1.37MHz followed by an 4017 to
divide by 10.
VFO worked perfect but the 10-diveder just wouldn't
work!!!!
I spend hours and hours to get it running, tried
several different IC's
(I expected speed problems etc) all with no
result.........
1.37MHz in ......NOTHING
out................
It was a sinple circuit : pin 8,13,15 to ground,
VCC on 16, 1.37MHz on pin 14,
and output at pin 12...... so stupid simple, that
it really is amazing that things are
not working.
Well, I decided to try my luck with an 4060
IC..........modified the VFO, now around 2192kHz,
divided by 16 to get 137kHz.
Well, that does work ,so, so......and with a large
amount of harmonics....2,3,4,5, etc times 137kHz
and all very strong well into the 5MHz
range..........
I think I need a lot of filtering to get rid of
this.................
So, with things already in this stadium getting so
unfortunate, I think it's better to stop
before I start loosing components like FET's or
what ever, because I can't imagine that
that will work without problems
either..........
Once again, sorry to say, but can't efford myself
to continue this way.
I do know that this is the real experimental stuff,
and I have done a lot in the past,
but for now not so enthiousiastic about this
project anymore.
Maybe later I'll pick things up again.
Meanwhile I will try to keep informed about the
136kHz scene here in the list; maybe doing some
listening...........
73 for now!
Dick (an unfortunate 136-TX
builder..........)
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