|
Hello
Stefan,
i
fully agree with you,it is all about the fun of doing experiments,if the
technicues are modern or oldfashioned doesn,t matter.
73
Victor
PS; I
work to live,I don't live to work
Hello Ken,
The thing is, i want to have
a very small VFO that consumes almost no power (say < 50 mA at 12V DC).
Also i have a f divide by 4 PA and would like to have a VFO that shows the
frequency from 472...479 kHz, without the need to divide by 4 in my mind. I
like to learn about simple analog oscillators by building them by myselfe, not
using the VFO of a ready to use HF TRX.
Furthermore it is no necessity for
me (as an individual) to do things that are up to date. Otherwise i would have
to decide to stop with the old fashioned amateur radio hobby and do things
that "all" men in my age (have to) do: Working as much as possible to
earn as much money as possible to consume as many useless things as possible,
marrying, building a house, driving an expensive car (not older than 5 years
of course), leaving the house in the morning in darkness to go to work and
coming home again in darkness, AND: Saying " I have no time because of my job"
and later "I have no time because of the grandchildren" or "My XYL said i have
to...". :-)
No, i prefer to build a simple Oscillator and i'm happy
when it starts to oscillate after a few hourse after starting the project. I
like the helpful comments from others and like to see the ongoing optimisation
of that VFO. This will not take 6 months but maybe rather 6 days (say 4 hours
per day) and this work is fun. Lastly i am glad to come on the band with
my MF station. It is the same with my PA and the complete LF stuff that
seems to work pretty well, obviously.
73, Stefan/DK7FC
Am
06.07.2012 19:19, schrieb Ken:
Dear
all.
I have been
following this thread from the start, and thought why build an Analog
Oscillator when you most likely have a good one already i.e. my old FT707,
if I tune from 3.776MHz to 3.832MHz, reduce the power into a 50 ohm dummy
load, tap off some of the output into a divide by 8, build two buffered 50
ohm outputs one to the tx the other to a frequency counter. It may be Heath
Robinson but it beats spending six months trying to build a stable
oscillator, also you can key the rig, ingenuity and a soldering iron? Most
of you will have an old transceiver which includes top band so you need only
divide by 4. As Mal would say that?s amateur radio at is best.
73s
Ken
M0KHW
Each to his own, but we would
be giving questionable technical advice, if
building a LC vfo was put foreword as
the preferred path to 500 , Racal's barlow-wadley
patent expired round 1970 and was
replaced with the digital - phase locked design in
the ra1771/2 , with 10 Hz stepping, round
the same time ...
Non of this is relevant now, with
the DDS , plenty of good ex-equipment 5
MHz standards about , that gives a 10:1
clock over head , all that's needed is a 500
band pass filter and output amp ,
If a CW tx is all that's needed , later
use the DDS as the conversion oscillator in
a down converter ..
OP QSO mode , good
question , the phantom of the Opera works in
mysterious ways .. its missing at
the moment from the latest version , keep the
old version for later in the year !
Sent:
Friday, July 06, 2012 9:41 AM
Subject: Re:
Aw: Re: LF: RE: Analog
oscillators
Getting One's Oscillator started
seems to be the problem at present. Perhaps a transverter is the
answer.
What has happened to Opera QSO
mode. I do not get any replies, others seem to favour Beacon
mode.
----- Original Message -----
Sent:
Thursday, July 05, 2012 9:27 PM
Subject: Re:
Aw: Re: LF: RE: Analog oscillators
I would say the most useful
thing to make would be a linear
transmit HF > 500 convertor .. then
all modes are possible , this is not 137 ,
ultra stable long qrss will not work , due to
the short qsb and varying skip
distance, this can be observed in qso or beacon mode ,
propagation will fail before the call is
sent !
Sent:
Thursday, July 05, 2012 9:16 PM
Subject: Aw:
Re: LF: RE: Analog
oscillators
building stable oscillators
was a topic in the eighties, and it depeded all on getting stable
components. Later developing OMs reported, that the oscillator for the
qrp-TRX was the most difficult and time consuming part in development. My
recomendation: Buy aready built up DDS-oscillator, available at
Funkamateur.de (herre with IQ-sigs) or ELV-Elektronik. It is
stable, shows little noise on LF/MF. Must just be built into a
enclosure. It is a time saving solution. But: DFCW is not possible,
and a keyed frequency divider must be added; I divide by factor ten
with CMOS-ICs. More details on request.
55, Hans-Albrecht, DK 8
ND
Hello
Ha-Jo,
Can you pull one of the xtals to cover the whole
band?
73, Stefan
Am 05.07.2012 20:57, schrieb [email protected]:
>
Dear all,
>
> the only parts I have bought so far for MF
(still beeing engaged in
> other developments) are two crystals:
6,5536 MHz and 7,0200 MHz, to be
> mixed with each other. The mixer
is another bipolar transistor, and its
> emitter current is being
keyed. A final source follower after the
> low-pass filter will
deliver the output to 50 ohms.
>
> The same solution I have
also used on LF.
>
> 73 Ha-Jo, DJ1ZB
>
>
>
|
|
