SATURDAY PM WAFFLE MODE

At one time it was thought that a 2M multimode could be pressed into service
as
an all-bands RX by a transverter with a synthesized oscillator climbing in
steps
of 2MHz, but now that approach has been overtaken by the various dongles
pluggable into PCs.

How the march of progress in the world of computers is changing
radically what counts as good ideas in radio!

The time cannot be far away now when anything with analogue stages,
other than in the intial RF amp for an RX, or the PA for a TX,
will seem to be positively pre-diluvian and vastly oversized.

So, where is the homebrewer in all this, for Gerald Youngblood was
just that before he started selling his own designed SDRs.?

For how much longer can rigs be sold for hundreds of £ / $ when all
that will be inside them is a bit of digital electronics little more
complex than a pocket calculator available for a tenner?

/SATURDAY PM WAFFLE MODE

"gareth" wrote in message
...
SATURDAY PM WAFFLE MODE

At one time it was thought that a 2M multimode could be pressed into
service as
an all-bands RX by a transverter with a synthesized oscillator climbing in
steps
of 2MHz, but now that approach has been overtaken by the various dongles
pluggable into PCs.

How the march of progress in the world of computers is changing
radically what counts as good ideas in radio!

The time cannot be far away now when anything with analogue stages,
other than in the intial RF amp for an RX, or the PA for a TX,
will seem to be positively pre-diluvian and vastly oversized.

So, where is the homebrewer in all this, for Gerald Youngblood was
just that before he started selling his own designed SDRs.?

For how much longer can rigs be sold for hundreds of £ / $ when all
that will be inside them is a bit of digital electronics little more
complex than a pocket calculator available for a tenner?

/SATURDAY PM WAFFLE MODE





yes computers ruin everything .....

On Sat, 30 Jan 2016, gareth wrote:

SATURDAY PM WAFFLE MODE

At one time it was thought that a 2M multimode could be pressed into service
as
an all-bands RX by a transverter with a synthesized oscillator climbing in
steps
of 2MHz, but now that approach has been overtaken by the various dongles
pluggable into PCs.

I haven't yet got one of those cheap USB things, but I can't help but
wonder if they are prone to overload. Little or no front end filtering
isn't going to be remedied by turning things digital at some point. So at
the very least, you'd be building front end filters for each band you
really wanted, to improve reception, just like in the old days.

For a long time, I've been intrigued by "the phasing method" for SSB. It
existed for a long time, yet somehow the potential didn't seem to be seen
in amateur radio circles. I remember one article about 1977 about
Independent SideBand, and the author said something like "the phasing
method isn't likely to be suitable for this purpose". Not then, but I
reread the article some years later, and realized "but if you're sending
SSTV for RTTY with the other channel, you will be able to get better
opposite sideband rejection". Since those modes require a single audio
tone into the transmitter, you can generate the audio tone using some
means that also provides the same signal but 90degrees apart, and there
goes all the worry about getting a decent audio phase shift network.

And it was later that that potential arrived at amateur radio (I have no
idea if it was talked about in professional circles), when much better
phasing rigs arrived, and then talk of DSP came along.

Even those phasing rigs were a development. All that fuss in the
seventies about better direct conversion receivers, try different mixers,
and all that, never amounted to much of an improvement. Then someone
showed a tiny direct conversion transciever in QST (it wasn't Wes Hayward,
but someone whose work has appeared in the same circles, but I can't
remember the name). The receiver had a diode ring mixer, but he actually
terminated it. Terminating such mixers were out there, there was a 1974
article in QST about this for VHF converters, but somehow it took some
time for the pieces to go together. Sometimes these things are right in
front of you, but it's not seen. Then Gary Breed had a fancy phasing
receiver in QST about 1986?, and then of course much more work on phasing
rigs like the R2.

Sometimes you have to go back to start again.

But anyway, I'm hesitant to think those USB things can be a match for a
good receiver with a good front end, but they certainly make the phasing
method so much easier. No need to get all those 1% tolerance resistors
and very accurate capacitors (and likely still have to match them), it's
all replaced by the conversion to digital. So I can certainly see those
USB things being used in conjunction with existing receivers, tapping off
the IF strip.



How the march of progress in the world of computers is changing
radically what counts as good ideas in radio!

The time cannot be far away now when anything with analogue stages,
other than in the intial RF amp for an RX, or the PA for a TX,
will seem to be positively pre-diluvian and vastly oversized.

So, where is the homebrewer in all this, for Gerald Youngblood was
just that before he started selling his own designed SDRs.?

One reason QRP became "movement" in the sixties was that so many had high
power that the challenge was disappearing. Drop to low power, and it
becomes a big challenge again, the antenna more significant, and of course
since it's low power (right when transistors were useful) it's easier and
cheaper to build. That seemed to cause a lot of building again. People
like the challenge. In shortwave listening, there are some who are buying
cheap am/fm pocket radios, and seeing how well they can do. It isn't
"better than with really good receivers" but the challenge is seeing how
well you can do without the fancy receivers. Likewise, people can build
single transistor transmitters, and see how well that can do, work on the
antenna to improve things.

And you can always look at homebrewing as something separate from
operating. Obviously in the early days, you didn't have much choice but
to build, and seeing how far you could get reflected that homebuilt
equipment. But even if building is "no longer practical", the challenge
is there. You can learn a lot from simple projects, and I dont' see the
supply of transistors with leads disappearing any time soon.


For how much longer can rigs be sold for hundreds of ? / $ when all
that will be inside them is a bit of digital electronics little more
complex than a pocket calculator available for a tenner?

Don't forget that that's already happening, those Chinese VHF/UHF walkie
talkies that cover more than the ham bands, they've gotten really cheap,
and surely rely on the new wave of "digital" receiver ICs.

Michael