how to choose a tube tester
JP
I working on repairing my first old radio--a Majestic 1A59EB. I would like
to test the tubes in it (41, 75, 80, 6A7, 6D6), but have no tube tester on
my wee bench. The testers I see for sale on Ebay seem to range between
$5-50 (Superior, Eico, etc.), then jump to testers that sell for over
$300-1000 (Hickok, military models, etc.).
So I was curious what models I could pick up for a reasonable price (under
$50 or so) that would test the tubes I need to test, have a decent range of
tube types that it can handle for my future projects, and not...to be
blunt, be a worthless heap of garbage from day one.
Any advice would be much appreciated--including better sources to buy tube
testers than Ebay.
Thanks much,
Jason
TubeGarden
Put the tube in the circuit you are going to use and listen. If you like it, it
is good. If not, you may change the circuit until you do :)
The alternative is test stuff you cannot hear. What does that accomplish?
Buy $50. worth of tubes and swap them into the radio and find the best sounding
of the bunch.
eBay is just another yard sale ;)
Happy Ears!
Al
Alan J. Marcy
Phoenix, AZ
PWC/mystic/Earhead
Rich Sherman
good.
Look for older model testers that have the old sockets
that accept 45's, 2A3, etc..
Personally I own an Eico 667 tester and don't always 'trust' what it is
telling me.
Som tubes read 110% and are garbage. Other's like my Svetlana 6650 read 35%
and are absolutely new and flawless.
The best Tube Tester is to have more than one. They are like Doctors, always
look for a second or third opinion before trading 'weak' measuring
Telefunken ECC83's that are actually only 1/2 way to the cleaners!!!
If you really want to test Power Tubes you have to do it at 'real' voltages,
not the wimpy 300 volts or less that the typical 'Mutual Conductance' tube
tester provide.
Look for the TV Military of Hickok 539 series or the Carmatic 123, those are
good testers.
Good luck,
Rich
"JP" <jpr...@igc.org> wrote in message
news:Z3uWa.1830$kP6...@newsread2.news.atl.earthlink.net...
Max Holubitsky
TubeGarden wrote:
> Hi RATs!
>
> Put the tube in the circuit you are going to use and listen. If you like it, it
> is good. If not, you may change the circuit until you do :)
I disagree with this. This guy is testing radio tubes, and it would be hard to
subjectively determine if the tubes are working properly. While it is true that a
tube tester is not a conclusive report on a tube's performance, it's sure nice to
be able to weed out the marginal and bad ones.
>
>
> The alternative is test stuff you cannot hear. What does that accomplish?
>
Improved sensitivity on the RF side of things, more power output, and a greater
chance that you won't have to change the tubes in the near future in the case of
marginal tubes. Can one really hear all these things without an extensive period of
evaluating the radio? I'd say checking the tubes is much easier, and then, when one
gets the chance to do some DXing, the performance will be there.
>
> Buy $50. worth of tubes and swap them into the radio and find the best sounding
> of the bunch.
>
Buying new tubes and replacing all of them may be cheaper than a tube tester for
one radio, but not in the long run.
The cheap testers test emission, and the expensive ones check transconductance. An
emission tester is fine if all you're doing is checking the occasional tube. Try to
buy one that has sockets for the tubes you want to test, and preferably one which
has recently been calibrated, and includes the data book. I have a couple testers
without the data books, and they are not good for much. Some of the tubes you
mentioned have very old fashioned bases, so make sure the tester you get has more
than the normal octal and 7 and 9 pin mini sockets that a typical late 50s or 60s
tester would have.
Personally I have a TV-7C, which is the Canadian military version of the famous
TV-7, and I use it to test tubes in anything I acquire, and to periodically check
their condition as preventative maintenance.
On and one more bit of advice, is buy a pre made tester, and not some kit. You have
no idea what the workmanship that went into the kit was - while it could be great,
it could also be a big mess that's never worked right.
Good luck
Max
Ian Iveson
If you need a tester at all, you need more than a cheap one. If you
worked in an old radio parts shop you just needed something not far
from a light-bulb tester. If you dump the occasional good valve,
who cares? Those testers don't tell you much. As Al says, you can
do that in your circuit.
The higher-priced ones are ranged mostly according to function,
voltage and current range, and quality. If you seriously want to
measure valve characteristics, that is what you need. And you need
to keep it calibrated, which is the real nightmare.
I have an AVO CT160 portable which was (slightly unfortunately) in
the Navy. It is about the minimum end of usefulness. I guess the
going price for such a thing would be a reasonable guide to the
minimum price of a useful instrument. It does a full set of
continuity checks and measures gm directly and fairly accurately
sometimes. It has only a few voltage settings for screen and anode
so is of limited use for plotting entire curves. It does have
continuous current settings though. And a pretty full set of
sockets. And it's cute. And it won't fall in value unless you
break it but consider shipping costs.
cheers, Ian
"JP" <jpr...@igc.org> wrote in message
news:Z3uWa.1830$kP6...@newsread2.news.atl.earthlink.net...
Lou D
I-177 military tester of Hickok design made by various manufactures. It is
well made and easy to use. They can be had at the $50 to $100 range.
Fred Nachbaur
Avoid simple "emission testers," and opt for transconductance (aka
"mutual conductance") testers. I really like my B&K Model 747B, largely
because of its compact size. (Like you, I have a very "wee" bench.)
Cheers,
Fred
--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects, Vacuum Tubes & other stuff: |
| http://www.dogstar.dantimax.dk |
+--------------------------------------------+
Jiri Placek
EICO 666
Bob Hedberg
Most tube settings are accurate. I've been using one for four years
now, and have gotten used to it. There are a a few updated charts, so
if you run across a tube with low readings and it doesn't seem right,
it may be the settings. Known NOS will really tell. Most settings
are right, and good tubes usually read from 100 to 120 %.
For reading really high transconductance tubes, however, take the
readings with a grain of salt. They sometimes read lower than they
really are.
I had a problem reading 12gn7's, and found that my Heathkit TT1 read
them correctly.
The 666 will read normal power tubes correctly, like 6550, 6l6, EL34,
etc, if properly calibrated.
Bob Hedberg
radio...@fast.net (Jiri Placek) wrote:
Bob H.
Just grab that plate in one hand, the chassis in the other,
and FEEL the power of tube audio!!!
(not literally, of course, just kidding. DON'T DO THAT!)
proletariat
MU150 are the lowest cost of the serious tube testers, with the TT-1 or
TV-7A/U being the picks of that group.
All are around $200, + a good calibration will run you $75 - $125
There is no good $50 tube tester. It is like saying I want to buy a serious
computer for $100
But your $300 investment will serve you well, and the great thing is, should
you decide to sell it, you should make money, as you will likely get over
$300 for a calibrated example of any of the above testers.
cowboy
You really want to
"JP" <jpr...@igc.org> wrote in message
news:Z3uWa.1830$kP6...@newsread2.news.atl.earthlink.net...
Fred Nachbaur
proletariat wrote:
> The Hickok 533A or 600A, the Heathkit TT-1, the TV-7A/U and the Sencore
> MU150 are the lowest cost of the serious tube testers, with the TT-1 or
> TV-7A/U being the picks of that group.
>
> All are around $200, + a good calibration will run you $75 - $125
>
> There is no good $50 tube tester. It is like saying I want to buy a serious
> computer for $100
That's not to say that you might not get lucky and find a bargain if
you're patient, and keep your eyes and ears open. Tube testers are sort
of a "fringe" item, and if you poke around in obscure second-hand stores
who knows what you might find. For instance, I got my B&K 747B for $50
Cdn (usually sell on ebay for between $150 and $250 US).
Cheers,
Fred
--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects: http://dogstar.dantimax.dk |
+--------------------------------------------+
Dwaine Garden
>
>
> proletariat wrote:
>
>> The Hickok 533A or 600A, the Heathkit TT-1, the TV-7A/U and the Sencore
>> MU150 are the lowest cost of the serious tube testers, with the TT-1 or
>> TV-7A/U being the picks of that group.
>>
>> All are around $200, + a good calibration will run you $75 - $125
>>
>> There is no good $50 tube tester. It is like saying I want to buy a
>> serious
>> computer for $100
>
>
> That's not to say that you might not get lucky and find a bargain if
> you're patient, and keep your eyes and ears open. Tube testers are sort
> of a "fringe" item, and if you poke around in obscure second-hand stores
> who knows what you might find. For instance, I got my B&K 747B for $50
> Cdn (usually sell on ebay for between $150 and $250 US).
>
> Cheers,
> Fred
Would you care to share your secret location?
Fred Nachbaur
Well, it's not secret at all. This particular bargain was from a
radio/TV repair shop that was "cleaning house" and getting rid of old
"obsolete" stuff. I missed out on the box of tubes and the VTVM, but got
the 747B.
The point I was trying to make is that if you keep your feelers out, and
are willing to be patient, the stuff is out there just waiting for you.
It can be on ebay, at local yard sales, second-hand stores (though many
of these are getting hip to the value of tube-related gear), Salvation
Army, GoodWill, newspaper ads, etc. Just follow your nose.
Ned Carlson
> If you are going to be working on pre WWII radios then I would recommend the
> I-177 military tester of Hickok design made by various manufactures. It is
> well made and easy to use. They can be had at the $50 to $100 range.
If he's doing mostly stuff from WW2 & prior I would second that.
I-177 can't test later stuff like 12AX7's, so they go for less than
other testers.
I'm partial to B&Ks but AFAIK, few B&Ks have sockets for antique
tubes like 80's, etc.
--
Ned Carlson Triode Electronics
25633 W Irving Park Rd Chicago, IL, 60634 USA
ph 773-871-7459 fax 773-871-7938
11AM to 7 PM CT, (1700-0100 UTC)
http://www.triodeelectronics.com/
Chuck Harris
box that is part of the set. It would be very easy to make one on
your own. The set cables into the "N" octal tube socket, and has
a group of 5 cables with bananna plugs, and 9, or 10 bananna sockets
that connect to the corresponding pin on the adapter sockets.
The latest charts have all of the simpler miniature tubes. When I
had mine, I had a book dated 1965, or so. I would bet that
Nolands Redneck Boatanchor site would have that book online.
-Chuck
firedome
the 12ax7s &c as the military also made an add-on unit for the 177
that enabled testing of later tubes, though it was kinda a pain to
use, lots of cable plugging-in etc. Did work well though. I finally
gave in and got rid of it for a TV-7D. Excellent machine.
Roger in NY
"Ned Carlson" <postm...@triodeel.com> wrote in message news:<pan.2003.08.02....@triodeel.com>...
Lou D
KS-15874-L2 Cardmatic with a full set of cards that I got for less than $50.
My I-177 was $40 , Eico 666 for $25, Hickok 800A was $80 and Hickok 540 was
$25. Still like the old 177 for the radio tubes, fast and reliable. Lot of
the stuff I found advertising on a small local AM station "Swap Shop".
"proletariat" <m...@myhouse.com> wrote in message
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Lou D
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