I've bought a lot of tube sets off of E-bay
and I agree with all this. The tubes have
been good in most of the sets I've bought,
and many still have the original manufacturer's
glass. Replacements are almost always cheap and
abundant, except for the notorious 1L6 used in
the tube-type T/Os and their clones. On the other
hand I've bought about 10 radios that use that tube
and none has ever arrived bad or gone bad in service.
The first T/O I bought on E-bay had a spare 1L6 tucked
into the little tube caddy in the back door!

Oz


Frank Dresser wrote:
"m II" wrote in message
news:UPc9d.37987$N%.31812@edtnps84...

RHF wrote:


DG,

Here are a few Vintage Radios on eBay:

Lots of nice stuff out there. I wonder about the tube supply though..how
hard is it to get the things these days?


There's still plenty of tubes. Most radios used common tubes, which were
produced in high volume. The military has surplused out pallet loads of
mil-spec radio tubes over the last couple of decades. Also, since the tubes
were common to most of the makers, there's still bushel baskets full of good
pulled tubes nobody ever threw out. I've bought plenty of used tubes at
hamfests, and nearly all are good. I usually pay fifty cents to a buck for
used tubes I know I can use. New radio tubes usually go for two to five
bucks. Some audio output tubes and rectifiers might go for more. There's a
couple of battery set tubes which are now pretty expensive.


I haven't looked lately, so I don't know supply or pricing.


Mostly it's not a problem If the radio tube supply ever gets tight, people
will be able to modify sets to use solid state replacements or TV tubes.
Most of the TV tubes are almost give away items now. If those TV tubes
don't get thrown out, somebody might be using them in radios in a hundred
years or so.


A long time ago, someone suggested a variable power supply for the
filament supply..the idea being that you could heat up the filaments in
a slow and orderly fashion and thereby extending their life
tremendously. It seemed to make sense as most lightbulbs fail at the
moment of being turned on. There are enough similarities that a
comparison may safely be made.


Don Klipstein says a soft start device might improve bulb life by only a few
percent. I'll take his word for it:

http://members.misty.com/don/bulb1.html#mll


Anyway, the heater of a tube runs much cooler than the filament of a light
bulb and ought to last much longer. I know there's a formula for
calculating the life of a filament vs. temperature. I don't know what it
is. I think there's a fourth power relationship, however. A little
temperature reduction increases lifespan dramatically.

Tube heaters run cool enough that they don't evaporate much material during
their lifespan. I think the heater failure mode is a little different than
a light bulb. The number one cause for heater failure in the AC/DC sets
I've worked on is a heater to cathode short in another tube.

Tubes fail, but they don't usually fail by opening up the heater. Emissions
go down as the tube ages. Heater to cathode shorts are a common problem.
Gas can get into the tube Grids can get damaged by overheating. Tubes
which use soldered pins can have bad connections.

Still, radio tubes are generally reliable. I think small signal tubes have
been estimated to have an average lifespan of 50,000 hours, longer if you
can accecpt reduced performance. My Hallicrafters SX-99 (1957) still has
all it's original tubes, and they all work fine.

Frank Dresser

A Grundig 960 is a copy of an old style shortwave rig on the outside but has
updated electronocs inside. It may be out of your price range but is maybe
the best of both worlds. I can't vouch for it's shortwave abilities but
they're probably not bad.

http://universal-radio.com/catalog/vintage/0960.html






"Doc Gorpon" wrote in message
...
I like old stuff and I want to get into hearing some talk radio outside of
my
area. I'm also on a budget. Will this suit my needs?


http://cgi.ebay.com/ws/eBayISAPI.dll...526781 1&rd=1

I have one. It "sounds good". Other than that, it sucks!
Tuning is "spongy". You can tune back and forth and NEVER get it exactly
where it needs to be. Full of images. Overloads on a random wire. Trust
me, it's junk...



"Chuck" wrote in message
...
A Grundig 960 is a copy of an old style shortwave rig on the outside but
has
updated electronocs inside. It may be out of your price range but is maybe
the best of both worlds. I can't vouch for it's shortwave abilities but
they're probably not bad.

http://universal-radio.com/catalog/vintage/0960.html






"Doc Gorpon" wrote in message
...
I like old stuff and I want to get into hearing some talk radio outside
of
my
area. I'm also on a budget. Will this suit my needs?


http://cgi.ebay.com/ws/eBayISAPI.dll...526781 1&rd=1

Frank Dresser wrote:

There's still plenty of tubes.

snipped for brevity....


Thank you for the insights. Things aren't as bad as I thought..



mike

"m II" wrote in message
news:GVl9d.41562$N%.5104@edtnps84...
Frank Dresser wrote:

There's still plenty of tubes.

snipped for brevity....


Thank you for the insights. Things aren't as bad as I thought..


In sense, many of the parts for modern radios are harder to find than the
parts for old radios. Such things as Application Specific Integrated
Circuits are oftentime unique to one particular radio. And there isn't an
inventory of common parts in repair shops, warehouses and drugstore tube
testers. These ICs are highly reliable, but not perfect and they can also
be damaged by other failures in the radio. The most practical way to fix
many problems on a newer radio is by swapping boards from other junk radios.
I really can't see the sort of future hobbiest repair interest in current
radios as we now have with old tube radios.

Frank Dresser

"Jim Hackett" wrote in message
ink.net...
I have one. It "sounds good". Other than that, it sucks!
Tuning is "spongy". You can tune back and forth and NEVER get it exactly
where it needs to be.

That's unfortunate. Real Grundigs got those details right. My Grundig has
a slow tuning rate, a steel dial cord on the tension side and a big
flywheel. There's no noticable backlash, even on SW. And, for anyone with
even the slightest ear to hand coordination, tuning just feels good.



Full of images.

Oh, yeah. My Grundig has plenty of images. But it's not as bad as it used
to be, back when the bands were filled with utility stations.


Overloads on a random wire.

I had a big attic wire. The radio loved it!


Trust
me, it's junk...




As I understand, plenty of people don't think much of it.

Frank Dresser

I have a 960 Grundig. It's attractive, and has good sound. Hook a disc
player or a digital shortwave to it, and it's a nice little amp. For a
budget oriented radio listener, the Kaito radios seem like a worthy
consideration. Darren





http://community-2.webtv.net/DEMEM/L...mes/page2.html