On Fri, 2 Dec 2011, NT wrote:



Does anyone other than John think there's commercial mileage in
modular radio now?

Not as portrayed, and certainly not as a general radio.

There have been articles about building in modular form and even some kits
that were modular, and of course it's a great form for experimenting, why
remake the whole radio if you want to try a new IF strip or add a new
detector? Or buy the modules you want to build up something, rather than
be stuck with what the complete radio the company sells.

But there can't be a general bus, one module takes its input from the
antenna or a previous module, and its output goes to the next module,
those have to be well isolated. The power supply is standard to each
module, the whole point of three terminal regulators was to make
regulation specific to boards rather than one big power supply feeding
everything. But control lines will be different depending on the function
of the module, some requiring lots of lines, others requiring few or none
at all.

And there's no way it would be for everyone. The average radio user
doesn't care, they just want AM/FM radio, nowadays not even AM and a radio
is a radio, once you have one for average use there's no need for
improvement.

A modular radio might be interesting to the hobbyist, which of course is
where the concept has travelled. It's there in all the VHF converters
described in the hobby magazines, getting extra coverage with a shortwave
radio at the cost of a "module", ie converter, rather than having to build
a whole new radio. It's the hobbyist that wants to try things, it's the
hobbyist that is interested in the radio in itself. They are the ones who
might want to do better on longwave, or listen to the police band (even
then, or a lot of that type of hobbyist, existing scanners are more than
enough).

For a small company aimed at the hobbyist, modules make sense. They dont'
ahve to offer multiple receivers, just enough modules for someone to put
together what they want. I long ago argued with a friend that if he was
going to go into a small electronic business, just selling boards made
sense, since then he's not involved in dealing with cabinetry. The
hobbyist can buy the modules and then take care of putting it in a case.

It's a fairly limited market, yet at one point was one that might do okay.
You can have a successful business without making loads of profit, and
indeed doing away with things like UL approval by using an existing AC
adapter or having the buyer come up with one keeps overhead down, as does
the lack of cabinetry. Find a market that really exists, and cater to it,
you may not be rich but the business may keep going.

I have no idea if the market is there anymore. I've been going through
old magazines lately, and it reminds me how much time and even money I
spent on magazines, the hobby electronic ones and the ham magazines, and I
feel detached to it as the magazines disappeared, virtually no hobby
electronic magazines in North America, and the ham magazines dwindling but
more important less available on newsstands than in the old days. The
magazines were pretty important, and I'm not sure they really have been
replaced with other things. If nothing else, they were way to keep track
of the companies that sold kits and parts.

A different way to look at it is to think about commercial shortwave
receivers. They have become really cheap, and fairly good. I paid
somewhere around $80 for a Hallicrafters S-120A (the transistorized one)
in the summer of 1971, the most I could afford, the cheapest receiver
I could find locally. It was junk, the only good thing about it was I had
no experience so I didn't know how bad it was for a bit. You can get a
Grundig Yacht Boy 400 (or whatever the same model in a different cabinet
is) for a hundred dollars, some of the other Etons for the same complete
with synchronous detector. For that matter, I am finding sw receivers
at rummage and garage sales now for pretty low amounts. That Grundig
Satellite 700 for 2.00 at the Rotary Club sale, that Sony ICF-SW1 at a
garage sale in September for 10.00 (and then about half an hour later an
Eton Mini 300 for 2.00 at another garage sale, though that is junk).

They are infinitely better than the old low end analog receivers.
People talk about buying all kinds of models, but nobody seems to think
that if a hundred dollars is seen as "disposable" then why not buy a radio
to modify extensively?

Buy one and put it into a bigger cabinet. Make it a desktop physically,
complete with a good tuning knob on the front panel. Even receivers with
up/down buttons can be tuned with a tuning knob. All those people who
judge a radio by "sound", they can put a nice big speaker in the cabinet,
though better to use an external speaker. Add better lighting to the LCD
display. Add that Q-multiplier. Add some filters if you can get some at
the proper IF frequency. The radio becomes the foundation to customize.
Add an FM IF strip and then feed the radio with converters to hear those
higher bands. Put some more front end selectivity in the box, yes
suddenly you'd have to tune it in addition to the tuning knob, but that's
the way it used to be on the good receivers anyway. It doesn't have
fine enough tuning? Then add a variable capacitor across the second
conversion oscillator (either directory or via a varicap), and you can get
a fine tuning knob that isn't linked to the BFO. For that matter, one
could splurge and add crystal controlled BFO, getting the frequencies to
be in the right place in relation to the IF filter.

What's wrong with current receivers that can be improved with a little bit
of work? Some things can't be fixed, but a lot of these new receivers
offer a pretty good foundation compared to what there was in the old days.

YOu start with a reasonably good receiver, you see the low cost so you
aren't afraid to hurt it, and you make it the receiver you want, just like
someone would want those modules for.

Michael