[TA Forbes]

That's quite a deal, Chuck!!

I have an 800A and it is pretty good. My only complaints are: 1. you must tweak a potentiometer to the "red dots" in order to measure uMhos; 2. No noise test. However, the "Hickok Circuit" was the industry standard from the 30s when it was patented until long after the patent ran out in the 50s. MANY name brand testers utilized the Hickok circuit in the 50s and 60s.

After researching the Weston sets, I have come to like them more than my Hickok. I like the 5KHz signal feature, and the Weston testers place higher voltage on the plate of the tube, resulting in, I believe, a more accurate result.

[Jamie]

I recommend that you don't spend a bunch of money of a tube tester when you first start out. The main priority is to just get a decent tester with sockets for all kinds of tubes. Many testers will only have four or five sockets, and you'll quickly realize that won't work.

I picked up a Knight RK-520 at an estate sale for $10 and, after recapping, it does a fine job for me. It has sockets for just about every style of tube and it will weed out the dead, shorted and weak tubes. It's not nearly as nice as a Hickock, but the money I saved allowed me to acquire a larger tube stash. If I have doubts about a certain tube, I just swap it out.

One of these days I will stumble across a good deal on a Hickock and then I will upgrade. If you are just starting out, you need some safety equipment, signal gen, soldering station,DMM, etc... and your money is better spent there...

[K7Sparky]

Your tube line up smells a lot like a AC / DC set, would like to hear more.

My experience is, the older tubes get and are still working well the less likely they are to go bad. If the manufacturer could pull a perfect vacuum and make a perfect seal they would last forever. The Getter inside the tube scavenges oxygen left inside after manufacture to help with less than perfect.

The mini tubes used in amplifiers for the first undersea ATT telephone cable from AL to WA (in 56 I think) was still working the last I had contact in area of ATT. The tubes were manufactured in lots of 10K and I forget the long burn in schedule. Any tube failed the entire lot was scrapped.

Watch hooking up the common lead on any AC powered test equipment. Measure the chassis common to common voltage first. Oldies plugs were not polarized and AC / DC units often had hot chassis.

First let admit I LOVE tube testers. They are most likely the first test equipment I ever got to operate. They were free to use at drug stores and supermarkets. Most places had a step stool to get up to set the switches, knobs and levers. Plug in a tube and actually see a meter move when the "test" was done.

My EICO has been home here for more than 30 years. The Hickok less than a year, just because I have wanted one for years, but never gotten around to buying.

Next: Jerry's' & Codefox statements that the radio (or whatever) is the best tube tester is spot on. Jerry's experience with tested tubes echoes mine. Your 7A tubes require Loctal sockets

A tube tester will tell you if the filament is good or there are pins shorted that shouldn't be.

You will get an indication if the tube may or not be good. In general if a tube tests in the "good" range it will work and if it is way down in the "poor" it probably won't. But that is only an indication as far as consumer affordable testers were concerned.

A tube may not work for V1, but works fine for V5 no mater what your tester indicates.

Tube testers are powered from 60 Hz. Most have B+ from a full wave supply which is 120 Hz. Not close to actual application frequencies.

TA - Thanks for the information on the Weston & HeathKit units. Didn't know about them and YOU BET it would be better. Something new on my want list.

As Ron says tapping the meter is often necessary. I remember doing it standing on a stool to get high enough to use a tester in a drug store.

My choice of beginning test equipment again echoes Jerry's (subject to reordering priority at any time).

1. DVM The cheepie from rat shack / harbor freight is more accurate than a mortal could afford in the 50's. A small warning if you are fortunate enough to have an old manual with voltage readings. Old VOM had nominal 20K / V input while DVM are in the meg range. If you find a lower voltage you have a problem, higher probably not.

2. Soldering / desoldering equipment. This is one area to spend more at the get go.

3. Scope, 10X leads and isolation transformer. Old is fine for broadcast radios. Many would place the scope in last place because of the learning curve.

4. Signal generator.

5. Lumped as depends on what you are trying to accomplish. Tube tester, inductance meter, cap meter, decade resistance box, decade capacitance box, lab power supply, dip meter, frequency counter

I readily admit I am a test equipment junkie.

[Eric T]

I agree with K7Sparky's prioritized list.

I have the first four and can do just about anything I need to do in regards to tube radios with that equipment.

Again, even a cheap DMM is plenty accurate enough. A more expensive model will also have useful features for doing things like measuring capacitors, signal frequency, etc.

Get a decent soldering set up. I have found that older solder sometimes needs more heat than a little 15 watt soldering pencil will give you. Having a soldering iron with adjustable temperature control is ideal.

My oscilloscope cost $50 on Fleabay. It is an old 50 mHz dual-trace basic Tektronix. Some people freak out over all the knobs and dials, but they are actually pretty easy to use once you get it set up for what you're trying to do. If you ever have a dead receiver and no visibly roasted parts, it can make finding a bad component quite easy. Good in, bad out = problem found.

Even a cheapie signal generator is good enough to align an AM radio. I have an old Heathkit SG-8 sig gen that cost $35. I recapped and it works just fine. I actually didn't need to re-cap it to make it work, but I figured an ounce of prevention, etc. I tested it with a frequency counter, and it's close enough for government work.

[TA Forbes]

K7Sparky: if you would like to correspond more about the Weston Instruments (798, 978, 981), shoot me a PM.

No O'Scope here. The issue with me and I am sure others is not how to use the instrument, but rather if the displayed waveform is correct or not.

For those who "real" technicians (Ron, Mike, Terry, Brenda, and many others), and not a self taught hacker like me, an O'Scope is indeed a valuable piece of equipment. A "real" tech can identify IF the waveform is correct, if bias that itshould ride on is at the right level, etc.....

Additionally, a 'scope requires a different level of skill when repairing/restoring/calibrating it.

For me, one of the MOST important things about working on anything is knowing what you do not know. Hence, while I agree that a 'scope is a valuable piece of test equipment, it is not something I currently have here.

[DeckApe]

I think I've said elsewhere on here... I own an Eico 666 tube tester. I'm still not sure what encouraged Eico to choose that particular model number, but the unit itself isn't bad, and can handle all tubes from four to nine pins. Eico's settings-charts are reported to be a little wobbly, so I recommend obtaining a few different editions and going with majority rules where possible.

Probably not the most popular unit around, but even in good shape you won't pay Hickok prices.

[K7Sparky]

The Eico I mentioned I've had for years is a 666. Beastly little guy that has never let me down.

I see they made an adapter that lets you test compactorons / sweeps / Novar base

Plenty of data on BAMA. The latest edition is what I sent. Everything that came in the box with a new one.

Also Eico include everything you need to develop tests for what ever tube you have that is not on a chart. I think Eico is under rated, just as Hickok is a bit over rated. (I need to duck and cover for that comment)

[TA Forbes]

There is a lot of discussion about the real value of the "dynamic conductance" testers like the Eico 666 and 667, both pro and con.

I like 'em. They are easy to work on and calibrate, and give in my opinion a valid and reliable result. They are simple to operate and the "shorts" test is always done before the tube test is done. After reading the manual I was convinced that the combination of plate emission and mutual conductance (Dynamic Conductance) was a valid way to test tubes. HOWEVER, Alan Douglas in his book did some very interesting tests comparing some Dynamic Conductance to other testers and his results indicated otherwise. (read -unreliable)

The only bad I have to say is that they: 1. Have no gas, noise, or "life" test; 2. Tend to "struggle" a bit when testing high power tubes; 3. The roll charts are notorious for having errors.

[jerryhawthorne]

You know, this thread might as well die. The poor guy that asked advise has not been back and if I where him I would have bailed out as well if I were new. Very few really addressed his question and went off subject on to how to fix mine and others. It's sad. Too much information that was not related to his original question although some good.
Welcome back "OD" if your still out there.
Jerry

[Arran]

One good tube tester make is Triplet, I don't know if they made Mutual Conductance models but they are well made and will tell you whether a tube is stuffed or no. I'm never actually seen a Weston tube tester but know that they had a good reputation in the analog volt-ohm meter market for years, if there was a Heathkit clone of a Weston it's probably a decent tube tester.
Most of us that play with a range of radios from different eras usually need at least two tube testers to cover the range of tube bases over the years. A tester that will test 001As and #45s will not usually test duodecal TV tubes from the 1960s. If you need to test foreign based tubes then all bets are off, I'm fortunate to have a RCAF spec military tube tester that covers some of them because the Canadian Military used to buy a lot of British crap, except for Phillips side contact bases.
Regards
Arran

[TA Forbes]

Hello Jerry/Arran/OD:

Jerry, I must contend that more info, even if it strays a bit from the original subject at hand, is always valuable. After collecting radios for greater than 40 years, I still learn some good tidbit from ramblings like those found in this thread, especially when it comes from "real deal" techs, like K7Sparky.

OD: lots of info here about a lot of stuff. Some of it may not apply to your current issue, but if you take the "other stuff" here and stow it away in your mental "bag of trircks," it will serve you well for future issues.

Arran: Triplett made two mutual conductance testers, the Model 3423, and the Model 3444. I have 3423, and it is a very acceptable performer for what it is. I have never owned a 3444, but it is a "laboratory" grade tester, and in my opinion a better instrument than the Hickok 539 series.
The Brits had some excellent testers made by AVO. Don't know if any of them made it to the Canadian Forces. When I worked with the Canadian Parachute Regiment I noted that they were equipped with an interesting combination of Brit and US gear.

[Arran]

Tom;
The RCAF tube tester I have is a Stark that was refurbished by Canadian Marconi in 1974 to accept more modern tubes like Nuvistors, Compactrons, and some funky European based tubes like rimlocks without using adapters. I haven't seen an AVO valve tester as yet, but that doesn't mean the Canadian forces didn't have some.
Regards
Arran

[TA Forbes]

Stark made some nice instruments!!

[Alan Douglas]

I don't see that any of the replies were irrelevant, and I would repeat two points: (1) you may not need a tube tester if you're only repairing one or two radios, and (2) there are far better places than ebay to buy one.

[jerryhawthorne]

Alan, you are right on your two points. Those are probably the most important. It just seems that things got very confusing for a new person. Seems the original OP has bailed out. The decision between a low end (emission) and a high end as for need was well defined early.
Jerry