Building a new shortwave tube radio
 

On Nov 11, 5:52*am, wrote:
*With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

*That means no regens, no DC bull****, and no plug in coils. It must
have production grade RF and IF coils, a bandswitch, and require
alignment. If sold as a kit the builder will need a RF generator and a
scope (or a spec an or CSM with a track gen).

*It should use off the shelf parts even if those shelves are bare, as
it is better to copy an existing item than design from scratch. I
would clone the Eddystone dial mechanism and the bandswitch and coils
from some Hallicrafters or Hammarlund set, they could be sold as
desperately needed replacement spares for the old sets too. I would
use a seeing eye tube mounted in a hole in the dial as opposed to a
meter movement, again, getting a run of new tubes made is possible if
you are buying several thousand. There are some surplus that could be
used if really needed too.

*I would use a separate power supply and speaker for several reasons.

*I would have the radio take in B+ and heater voltage and put out 600
ohm +4 audio. A regular supply could be used at home or car battery
and a switchmode brick for B+. A headphone jack would be supplied off
this tube.

*The set should cover 500 kHz to 30 MHz, AM, SSB and CW, with a
product detector of course. A 455 kHz IF is needed so as to use common
mechanical or crystal filters, which are optional. There should also
be a 455 kHz IF out for an external synchronous detector.

Any other comments?


The need for testgear to align the IF will wipe out 99.9% of any
potential market.

As pointed out, its going to be far too expensive. If you took that to
heart and tried to make something far cheaper, regeneration, although
a definite compromise, is a dead sure way to cut costs a lot, and has
angelic AGC performance. I recall a simple 3 valve 1930s regen set
giving rock steady audio on a signal even an exceptionally complex
modern dx set couldnt stabilise.


NT

Building a new shortwave tube radio
 

On Nov 25, 6:44*pm, NT wrote:
On Nov 11, 5:52*am, wrote:









*With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

*That means no regens, no DC bull****, and no plug in coils. It must
have production grade RF and IF coils, a bandswitch, and require
alignment. If sold as a kit the builder will need a RF generator and a
scope (or a spec an or CSM with a track gen).

*It should use off the shelf parts even if those shelves are bare, as
it is better to copy an existing item than design from scratch. I
would clone the Eddystone dial mechanism and the bandswitch and coils
from some Hallicrafters or Hammarlund set, they could be sold as
desperately needed replacement spares for the old sets too. I would
use a seeing eye tube mounted in a hole in the dial as opposed to a
meter movement, again, getting a run of new tubes made is possible if
you are buying several thousand. There are some surplus that could be
used if really needed too.

*I would use a separate power supply and speaker for several reasons.

*I would have the radio take in B+ and heater voltage and put out 600
ohm +4 audio. A regular supply could be used at home or car battery
and a switchmode brick for B+. A headphone jack would be supplied off
this tube.

*The set should cover 500 kHz to 30 MHz, AM, SSB and CW, with a
product detector of course. A 455 kHz IF is needed so as to use common
mechanical or crystal filters, which are optional. There should also
be a 455 kHz IF out for an external synchronous detector.

Any other comments?

The need for testgear to align the IF will wipe out 99.9% of any
potential market.

As pointed out, its going to be far too expensive. If you took that to
heart and tried to make something far cheaper, regeneration, although
a definite compromise, is a dead sure way to cut costs a lot, and has
angelic AGC performance. I recall a simple 3 valve 1930s regen set
giving rock steady audio on a signal even an exceptionally complex
modern dx set couldnt stabilise.

NT

One of the very reasons I DON"T like regens and direct conversions is
"No Alignment".

You need to have some kind of sig gen and preferably a scope. That's
a feature, not a bug.

Any hamfest in the US will net a working scope for a twenty dollar
bill and probably a usable RF generator for a similar sum. The guitar
amp ****s will part them out for the tubes and throw them in the
dumpster often as not.

In a pinch a grid dipper and a solid state RF probe attached to a DMM
will work.

Building a new shortwave tube radio
 

On Nov 21, 10:07*am, "Steve" wrote:
Hate to say this but you are doomed to fail from the start.
Why? There are PILES of tube type SW receivers available
now FAR cheaper than you could build one.

Hey, I get it. It'd be a fun project. I've thought about doing
something like this myself but seriously consider the cost.
Not just of the parts but the time involved in the design,
marketing, and *liability insurance*. Bet you didn't think
about that one!
* * * * * * * * * * * * * * * * * * * * * * * * * Steve

Liability insurance is tattooing "SUE ME" on your butt cheeks.

The general aviation industry nearly put ITSELF out of business by
answering every lawsuit with....you guessed it...more liability
insurance. The scuba diving industry instituted a certification
program and convinced all the attorneys that if a noncertified diver
killed himself by the traditional methods (embolisms or drowning)
juries would just laugh at them. Sport diving equipment companies do
not carry PL coverage except for tank explosions out of the water. No
one sues them for diving accidents. If they did they'd get the keys to
an empty warehouse. The sport diving companies are all turnips,
judgementproof. The COMMERCIAL diving companies are very funny as to
whom they will sell. The few eccentric hobby hard hat guys will attest
to this.

You can buy scuba equipment for a lot less today than thirty years
ago, in adjusted dollars. Airplanes have gone up by a factor of three
or four or five.

Buy legal insurance, and incorporate yourself so that you can not be
construed to have a personal holding corporation. But never buy PL
insurance or if you do have it strictly limited to a circumstance
which is incidental.

As to the piles of existing sets, yeah, there are-most are in bad
need of restoration. And most of them weren't worth a **** new. The
few good ones are carefully husbanded. The surplus Collinses and
Hammarlunds are about gone.

Building a new shortwave tube radio
 

On Nov 25, 6:28*pm, NT wrote:
On Nov 16, 4:23*pm, Michael Black wrote:









On Wed, 16 Nov 2011, dave wrote:
On Wed, 16 Nov 2011 08:01:11 -0600, D. Peter Maus wrote:

On 11/15/11 19:05 , flipper wrote:
On Fri, 11 Nov 2011 10:45:09 -0600, "D. Peter Maus"
*wrote:

On 11/11/11 08:42 , Lord Valve wrote:
If the **** hits the fan, most hi-mu triodes will work well enough to
build a regen set. Where to get the B+ is the problem.

That simple, since there's only a few tubes.

9v "transistor" batteries in series. *It doesn't take that many to get
reasonable B+ and since tubes are low current, it's reasonable.

Of course, towards the end of the life of tubes, one could get some that
ran off 12v, intended for use in car radios. *Not so useful now since they
were produced in a limited time span as transistors were taking over, so
quantity is relatively limited.

The R392 ran off 24 or 28 volts, using those low plate voltage tubes. *Of
course, it had a lot of tubes so the filament drain was large.

Of course, some people experimented with low voltage on regular tubes. *A
loss of gain, but sometimes that was a good thing.

* * Michael

In the 19-teens it was common to run triodes with no negative bias,
and very low V_anode, like 20-30v. It worked, and cuts HT battery
cost, but of course distorts the grid signal.

NT

Sounded like ****, IOW.

Common tubes usually start working okay at 45 to 90 volts. The R-392
used selected tubes at 24-28 volts, and works okay, but not as well as
if they had had more. Collins S/Line used 150 volt B+ for what that is
worth.

Building a new shortwave tube radio
 

On 11/19/2011 1:40 AM, wrote:
[...]
Wow.

I remember listening to YOU-and Dr. Pierce-on the first regen I ever
built when I lived in Texas, about ten miles from the Louisiana line
on that shortwave station the NA bought time on. I did not always
agree with what you said but I damn sure backed your right to say it.
Pierce was really an intelligent person. I read the biography on him
by Robert Griffin, great read.



Yes, Dr. Pierce was and -- Dr. Griffin is -- a person of exemplary
quality. A privilege to know them, indeed.


Louisiana is a seriously warped state. Texas was screwed up in some
ways but Louisiana with its nightmarish hodgepodge of laws built on
four different legal systems and general laissez-les-bon-temps-rouler
attitude is Third World.

Regens are a pain in the ass. The best regen ever built was probably
the National SW-3, or for low frequency work the old Mackay Marine
set. Lindsay is full of **** when he says the homebrewer can better it
with moderate effort.And even so any mediocre superhet will outperform
it in some ways. My late forties Zenith console will separate stations
the SW-3 won't. But they are interesting to build-once-like the
crystal set, which can be run into a hi fi amp and give good local
station performance. My regen was the two tube set in the Romney book
which Lindsay also published. The SW-3 was far better-it would copy
ham CW on 80 and 40 consistently and even SSB with a good signal. The
homebrew was good for WWV and Radio Havana and that was it.



Even with more than four decades of radio under my belt, I still
haven't owned a regen -- though I've played with a few.

My next receiver will be an SDR. Eliminating all but one conversion
stage (since the SDR goes straight from RF to I/Q baseband) and
doing all the filtering and demodulation with perfect mathematical
accuracy in software not only gives you tremendous dynamic range and
filtering capability, but it makes the recovered audio almost
supernaturally clean-sounding.

Listening to a good SDR into a high-fidelity sound system for the
first time is like discovering that pillows had been strapped to
your speakers, and gravel had been stuck to your voice coil, for all
these years -- and finally removing them.


With best regards,


Kevin, WB4AIO.
--
http://nationalvanguard.org/
http://kevinalfredstrom.com/

Building a new shortwave tube radio
 

On Nov 26, 5:54*am, wrote:
On Nov 25, 6:44*pm, NT wrote:



On Nov 11, 5:52*am, wrote:

*With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

*That means no regens, no DC bull****, and no plug in coils. It must
have production grade RF and IF coils, a bandswitch, and require
alignment. If sold as a kit the builder will need a RF generator and a
scope (or a spec an or CSM with a track gen).

*It should use off the shelf parts even if those shelves are bare, as
it is better to copy an existing item than design from scratch. I
would clone the Eddystone dial mechanism and the bandswitch and coils
from some Hallicrafters or Hammarlund set, they could be sold as
desperately needed replacement spares for the old sets too. I would
use a seeing eye tube mounted in a hole in the dial as opposed to a
meter movement, again, getting a run of new tubes made is possible if
you are buying several thousand. There are some surplus that could be
used if really needed too.

*I would use a separate power supply and speaker for several reasons.

*I would have the radio take in B+ and heater voltage and put out 600
ohm +4 audio. A regular supply could be used at home or car battery
and a switchmode brick for B+. A headphone jack would be supplied off
this tube.

*The set should cover 500 kHz to 30 MHz, AM, SSB and CW, with a
product detector of course. A 455 kHz IF is needed so as to use common
mechanical or crystal filters, which are optional. There should also
be a 455 kHz IF out for an external synchronous detector.

Any other comments?

The need for testgear to align the IF will wipe out 99.9% of any
potential market.

As pointed out, its going to be far too expensive. If you took that to
heart and tried to make something far cheaper, regeneration, although
a definite compromise, is a dead sure way to cut costs a lot, and has
angelic AGC performance. I recall a simple 3 valve 1930s regen set
giving rock steady audio on a signal even an exceptionally complex
modern dx set couldnt stabilise.

NT

*One of the very reasons I DON"T like regens and direct conversions is
"No Alignment".

*You need to have some kind of sig gen and preferably a scope. That's
a feature, not a bug.

*Any hamfest in the US will net a working scope for a twenty dollar
bill and probably a usable RF generator for a similar sum. The guitar
amp ****s will part them out for the tubes and throw them in the
dumpster often as not.

*In a pinch a grid dipper and a solid state RF probe attached to a DMM
will work.


If I were designing such a product, I'd do everything in my power to
avoid end user alignment with testgear, for one very simple reason: it
wipes out 99.9% of your potential customers, its business suicide.

Perhaps one could use resonators instead of LCs, if you dont like the
interstation garbage of agced reaction.


NT

Building a new shortwave tube radio
 

On Nov 27, 4:08*pm, NT wrote:
On Nov 26, 5:54*am, wrote:



On Nov 25, 6:44*pm, NT wrote:

On Nov 11, 5:52*am, wrote:

*With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

*That means no regens, no DC bull****, and no plug in coils. It must
have production grade RF and IF coils, a bandswitch, and require
alignment. If sold as a kit the builder will need a RF generator and a
scope (or a spec an or CSM with a track gen).

*It should use off the shelf parts even if those shelves are bare, as
it is better to copy an existing item than design from scratch. I
would clone the Eddystone dial mechanism and the bandswitch and coils
from some Hallicrafters or Hammarlund set, they could be sold as
desperately needed replacement spares for the old sets too. I would
use a seeing eye tube mounted in a hole in the dial as opposed to a
meter movement, again, getting a run of new tubes made is possible if
you are buying several thousand. There are some surplus that could be
used if really needed too.

*I would use a separate power supply and speaker for several reasons.

*I would have the radio take in B+ and heater voltage and put out 600
ohm +4 audio. A regular supply could be used at home or car battery
and a switchmode brick for B+. A headphone jack would be supplied off
this tube.

*The set should cover 500 kHz to 30 MHz, AM, SSB and CW, with a
product detector of course. A 455 kHz IF is needed so as to use common
mechanical or crystal filters, which are optional. There should also
be a 455 kHz IF out for an external synchronous detector.

Any other comments?

The need for testgear to align the IF will wipe out 99.9% of any
potential market.

As pointed out, its going to be far too expensive. If you took that to
heart and tried to make something far cheaper, regeneration, although
a definite compromise, is a dead sure way to cut costs a lot, and has
angelic AGC performance. I recall a simple 3 valve 1930s regen set
giving rock steady audio on a signal even an exceptionally complex
modern dx set couldnt stabilise.

NT

*One of the very reasons I DON"T like regens and direct conversions is
"No Alignment".

*You need to have some kind of sig gen and preferably a scope. That's
a feature, not a bug.

*Any hamfest in the US will net a working scope for a twenty dollar
bill and probably a usable RF generator for a similar sum. The guitar
amp ****s will part them out for the tubes and throw them in the
dumpster often as not.

*In a pinch a grid dipper and a solid state RF probe attached to a DMM
will work.

If I were designing such a product, I'd do everything in my power to
avoid end user alignment with testgear, for one very simple reason: it
wipes out 99.9% of your potential customers, its business suicide.

Perhaps one could use resonators instead of LCs, if you dont like the
interstation garbage of agced reaction.

NT

Of course a valve radio is business suicide to begin with, performance
per dollar has come a long way since the valve era. Number of valve
radios currently on the market is zero, so no-one has managed to make
them compete with 30cent ICs and 2cent transistors.


NT

Building a new shortwave tube radio
 

On 11/27/11 10:18 , NT wrote:
On Nov 27, 4:08 pm, wrote:
On Nov 26, 5:54 am, wrote:



On Nov 25, 6:44 pm, wrote:

On Nov 11, 5:52 am, wrote:

With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

That means no regens, no DC bull****, and no plug in coils. It must
have production grade RF and IF coils, a bandswitch, and require
alignment. If sold as a kit the builder will need a RF generator and a
scope (or a spec an or CSM with a track gen).

It should use off the shelf parts even if those shelves are bare, as
it is better to copy an existing item than design from scratch. I
would clone the Eddystone dial mechanism and the bandswitch and coils
from some Hallicrafters or Hammarlund set, they could be sold as
desperately needed replacement spares for the old sets too. I would
use a seeing eye tube mounted in a hole in the dial as opposed to a
meter movement, again, getting a run of new tubes made is possible if
you are buying several thousand. There are some surplus that could be
used if really needed too.

I would use a separate power supply and speaker for several reasons.

I would have the radio take in B+ and heater voltage and put out 600
ohm +4 audio. A regular supply could be used at home or car battery
and a switchmode brick for B+. A headphone jack would be supplied off
this tube.

The set should cover 500 kHz to 30 MHz, AM, SSB and CW, with a
product detector of course. A 455 kHz IF is needed so as to use common
mechanical or crystal filters, which are optional. There should also
be a 455 kHz IF out for an external synchronous detector.

Any other comments?

The need for testgear to align the IF will wipe out 99.9% of any
potential market.

As pointed out, its going to be far too expensive. If you took that to
heart and tried to make something far cheaper, regeneration, although
a definite compromise, is a dead sure way to cut costs a lot, and has
angelic AGC performance. I recall a simple 3 valve 1930s regen set
giving rock steady audio on a signal even an exceptionally complex
modern dx set couldnt stabilise.

NT

One of the very reasons I DON"T like regens and direct conversions is
"No Alignment".

You need to have some kind of sig gen and preferably a scope. That's
a feature, not a bug.

Any hamfest in the US will net a working scope for a twenty dollar
bill and probably a usable RF generator for a similar sum. The guitar
amp ****s will part them out for the tubes and throw them in the
dumpster often as not.

In a pinch a grid dipper and a solid state RF probe attached to a DMM
will work.

If I were designing such a product, I'd do everything in my power to
avoid end user alignment with testgear, for one very simple reason: it
wipes out 99.9% of your potential customers, its business suicide.

Perhaps one could use resonators instead of LCs, if you dont like the
interstation garbage of agced reaction.

NT

Of course a valve radio is business suicide to begin with, performance
per dollar has come a long way since the valve era. Number of valve
radios currently on the market is zero, so no-one has managed to make
them compete with 30cent ICs and 2cent transistors.


NT


Valves have a place in audio, for the truly faithful. But then,
audio only requires a few valve types, frequencies are easily
managed, and circuitry remains stable for much longer periods of
use. Whereas radio applications require more sophisticated valve
construction, and significantly different valve types for given
applications, to accomodate frequencies that stretch from 10X to
100000X audio frequencies.

What's comforting in radio with valve technology, is the general
sense that the technology itself is accessible. And widely
understood to be more forgiving. That valves may be removed, tested,
and replaced by the techologically limited, and operated under
conditions that would destroy solid state. Whereas, SS receivers,
self service requires a much higher level of skill, with a much
lower threshold of abuse. For those with limited technological
experience, this can be daunting. Especially, as in the case of this
receiver, during an emergency, where supply lines are uncertain, and
technical support is nonexistent.

I can see where the OP is coming from. Build an accessible
receiver that's fairly forgiving to extremes in noise, signal
levels, voltage, and hostile events, and you'd have a generally
useful rig for the general population in an emergency. It's a nice
thought.

But as has been pointed out here multiple times, SS technology in
a proper design has proven more resistant to EMP than generally
believed, operating voltages are easier to generate, and manage,
power requirements are lower, and performace of the technology is
dramatically improved since the days of valve receivers. All at a
fraction of the cost. And in an emergency, valve supplies will be
just as short as SS components.

All of which points to the fact that a well designed kit radio for
use in emergencies would be more like the Ten-Tec 1254, than it
would be like a Hallicrafters S-40. And the Ten-Tec 1254 is a kit,
costs $200, and requires no user alignment, but offers significant
performance across the spectrum from LF through HF.

In a package that's available now.

Building a new shortwave tube radio
 

On Sun, 27 Nov 2011, NT wrote:


If I were designing such a product, I'd do everything in my power to
avoid end user alignment with testgear, for one very simple reason: it
wipes out 99.9% of your potential customers, its business suicide.

Perhaps one could use resonators instead of LCs, if you dont like the
interstation garbage of agced reaction.


And Heathkit is the model for that. They'd prealign tuned circuits,
they'd have certain stages as preassembled modules, they'd build some
relevant test equipment into the equipment (like those tv sets with some
sort of metering in the back). One I always liked was a scanner, they
included some parts to make up a 10.7MHz oscillator and mixer. The
oscillator would provide the signal to align the IF strip, and then you'd
mix the local oscillator with this outboard oscillator/mixer to get a
signal on the signal frequency, to align the front end.

Heathkit of course did design for the beginner, I gather once they had the
instructions together they found people who had never put a kit together
to follow the instructions so they could make sure they made sense (and if
followed properly, would result in a working piece of equipment).
Despite the fuss about Heathkit being for the hobbyist, they always had
taht color tv set, that musical organ, that boonie bike, that were
aimed at people who just wanted something cheaper, and were willing to
put some time into it. But that's why Heathkit shut down the kits, with
time the sorts of things their was interest in got so complicated (and
parts so small) that it was no longer cheap to come up with the
instructions, pack the kit compared to just building it at the factory.

As for ceramic resonators, I think that is a key point. Design is the
overall results. When companies put in ceramic resonators in everyday
radios, they did away with a large part of the alignment, so even if the
resonators were more expensive than IF transformers (I don't know) the
reduction in alignment time was still significant.

As I pointed out, move to a higher IF, you may pay more for an IF filter,
but you can do away with the need to gang the front end tuning with the
local oscillator, which simplifies things mechanically but also gets rid
fo a lot of troublesome alignment. It's relatively easy to get two stages
of front end tuning to align together, just go for a peak, but ganging it
with a local oscillator is more complicated.

The superhet alone is a concept that complicates something to make other
things easier. Make things more complicated, the mixer and oscillator,
and you dont' have to fuss with multiple stages on the RF frequency.

Sometimes the "simplest" solution ends up with more work than the more
complicated one.

Michael

Building a new shortwave tube radio
 

On 11/10/2011 9:52 PM, wrote:
With the survivalist market as well as the DIYers who would build a
kit I have given thought to the idea of building a new tube shortwave
receiver as a usable, practical set.

...

Any other comments?

As I once pointed out, long ago, now, in an amateur group, what needs to
be done is to build a radio equiv to how PCs are now done.

First you would have a generic case, these could be made by anyone, in
any design. The would provide the user with an abundance of choice in
the looks of the rig.

Next, each section of the radio would simply be a plug in card, to a
"mother board." You would have an rf section, which could cover any and
all bands, depending on construction, it would simple plug into one of
the slots on the motherboard. Audio, rf, filter, conversion, etc., etc.
could be done this way.

You would have a basic set of all sections, and could expand, or upgrade
as you would have -- or as becomes available.

It would change the face of radio, SW radios would become as numerous as
PCs -- well, almost.

Most any small manufacturer could enter the market, and provide a case,
rf section, audio section, etc. -- and expand from there, if they choose.

I simply can't get enough interest ... but the radio could be just am,
am fm, am-fm-sw, am-fm-sw-vhf, am-fm-sw-vhf-uhf, am-fm-sw-vhf-uhf-shf,
or any possible combination wanted ... this is an idea whose obvious
advantage, for consumers, is simply screaming out for production!

Later, if one wished, he could just buy a larger standard case, move his
receiver components over, buy a larger power supply, and drop in the
appropriate transmitting section(s.)

We simply wait for the radio to leave the age of the horse and buggy ...

Regards,
JS