I think i see what you are saying, the leads continue into the glass and looks like they are not broken anywhere

electrical continuity, a complete circuit, a multimeter set in the ohm will do fine, the heater should be a few ohms, if not then it is a open circuit, burned out, will not work.

I don't have a multimeter.. All i can do to check the continuity is look as far as i can in the tube to see any shorts, but i can only look so far, but if the Sencore is not lighting the filaments, and not giving juice to the tube i would assume there are problems.. It did fail both cutoff and emissions and the HK shorts, when the filaments where lit up. it's probably burnt out.. Im looking for another Tube while i still have the extra $ to spend, and so far im not having any luck..

These old round CRT's don't generally fall out of the sky. You'll need to be patient, and then be in the right place at the right time. They're out there, but not usually right now, and real cheap. CRT's were never stock piled by repair shops like the common little tubes in our TV's. JMO

Kevin

Problem is is that i have the extra $ now, i may not have it when one pops up, you know how things usually work, something pops up, bills etc wanting to take our money.. Plus if i don't get this project going and fixed, my interest will probably become lost, and it will just sit back in a corner somewhere..

If it's 12kHZ I might have trouble hearing it. I suppose it would also vary in loudness quite a bit depending on the specific components, also background noise. I'll pay closer attention the next time I use it.

You can get a multimeter with continuity test for as little as $3 at Harbor Freight. Their ultra deluxe meter costs about twenty, and does just about everything you would ever need a meter to do to fix your television.

You can also build a continuity tester with something like a couple of C batteries, and a radio pilot lamp, like a #44-the bulb should light if the filament is intact. We only keep yammering on with this filament thing as it is very, very rare for a crt filament to blow-usually everything else in the picture tube goes bad before the filament fails.

Than why is the Sencore not powering the filament? I think when the Sencore does Tube tests it powers up the filament, it has done that on every set i've tested.. It's not the Sencore, because i went and tested another set i have to make sure..

That doesn't change the fact you need a meter when working on one of these sets. You'll find many uses for it beyond TVs.

Right, a decent meter should be the first tool you buy! Don't forget a set of probes too, mine have pointy tips and aligator clips that are interchangable.

Yes, get a $3 meter from Harbor Freight or whereever, it won't be the best but will do 90% of what you need it for, which is voltage, continuity, and resistance testing. Don't overlook that the filament wires may not be soldered well in the CRT plug.

perhaps the tube went to air and the filaments lit and burned out ? go over it with a magnifying glass and see if there are any holes or cracks ? they have low priced meters at walmart , one is like $10 and the other for around $25 is auto ranging , found in the auto dept

mike

Amateur Electronic Supply in Milwaukee sells Velleman multimeters for about $10. They aren't incredibly fancy (just one large knob on the front panel below the display for range changing and power switching, as well as the jack panel), although they do have a transistor and diode test function. I purchased one, albeit a more deluxe version, about five years ago, as I am rebuilding my toolbox (left most of my tools back at my former residence when I moved here eleven years ago). This meter works well enough for my purposes and is my first new item of test gear; it should also work well for you, if all you are interested in at this point are continuity testing and voltage readings -- although the transistor and diode test function could come in handy for you if you ever get an older transistor portable radio with plug-in transistors, such as the Zenith Royal 500 series or one of the solid-state Transoceanics.

Amateur Electronic Supply's website and physical street address are as follows:

Amateur Electronic Supply
5710 West Good Hope Rd.
Milwaukee, WI 53223

Toll free order line: 800.558.0411
AES web site: www.aesham.com

You can also order an AES catalog on the website; it's been a while since I used that link as I am on their mailing list, so I can't tell you at the moment where it would be on the home page.

You do not need to be a radio amateur to order from AES; many non-hams order equipment such as radios, digital TV antennas, etc. from them all the time.

73 (best of regards) and good luck restoring your antique Admiral TV. As I think I mentioned to you in another post, it's a great feeling to get these old sets working again as they did when they were new. Don't forget, you will need an ATSC->NTSC converter box and probably an outdoor antenna to receive digital TV signals on your set, although it will work with rabbit ears if there are still LP (low power) or translator stations on VHF channels in your area.

BTW: Don't expect to see or hear anything on channel 1 (I think your Admiral TV, being a 1948 model, has a 13-channel tuner). The FCC originally reassigned the frequency range (originally 44-50 MHz) to other services around 1949 or so; in fact, this range was eventually realigned and became, in the early 1950s, what is now the amateur six-meter band.

That is true, I will get one in the near future.... theres a couple of other things i would like to get, But i just have to learn how to use test equipment, some if it is hard, and i think requires alot of math to figure out reading etc.

To be off subject.. When i called the 800 number of wmicronics.com first time i got a hold of someone, the second time i called, i got an answering service in reference to a Doctors office.. I thought that was kinda weird, than i called the regular number, and the same guy answered and said he is doing research or something about the model, and would call back Monday, than i read the threads on here, so when or if they call back, im going to say i heard to much bad news about your site, and don't trust you..

Hawkeyeguy says that a museum in Ohio is suppose to open soon and is going to have the equipment to rebuilt tubes..

Good news. My TV man picked up the chassis today and he was looking at it, and the Power transformer is good, and the other high voltage trannys are good, was able to get sound and somewhat a picture with his test tube.. Bad news is that the Picture Tube is dead, open filament.... It was a cap like you all said that was making the noise and smoking, and i think the vacuum tubes are all fine aswell..He also said a 12KP4 tube would work also.. So now im desperately looking for a picture tube, and no im not desperate enough to pay alot more than what there worth.. So I'm on the hunt for a 12LP4 or a 12KP4..

You have a Sencore CR-70 but don't have a basic multimeter??? A meter should be your first piece of test gear. Also, I gather that you don't have much experience with vintage electronics seeing as you plugged in this set without giving it a thorough check-out. I think you need to learn basic electronics and learn how a VOM works. In addition you need to learn quirks of tube gear and the dangers within, especially TV sets. I would get books, and study and learn all you can. This is a great place to get info but you have to have a solid foundation of basics in order to move ahead.