View Full Version : alignment generators ?


Tube TV
10-26-2007, 01:30 AM
Wats the differance between a television alignment generator and a sweep generator .
Aso what is a good book that has information on television alignment .
any suggestions ?

Thanks Murray .
I got this heathkit off of craigslist vancouver for 10 bucks:banana: , should be here in a few days .
Ayone know how to run it , I dont .

blue_lateral
10-26-2007, 01:41 AM
Well, it's probably a sweep generator that does the correct frequencies for TV IF's. Judging from it's looks, I would bet it's for 21mc IF's, I use a B&K 415, but thats for 42mc IF's. I have an Eico that can do 21mc, but I don't know for sure it still works.

You will also need an oscilloscope and a VTVM for sure, and some other stuff like bias boxes, matching pads, demod probes, and maybe some crystals or a marker generator.

Looks like a nice unit. Did it come with a manual?

John

Tube TV
10-26-2007, 05:28 AM
I restored a Heathkit IO-12 oscilloscope so I got that . I still have to get the demodulator probe and a crystal probe ,
Also restored 2 heathkit VTVM's .
I am supposed to be getting a photocopy of the manual . I read somewhere that it has a crystal in it , I think it plugs into to the front on the left .
there was a good website for heathkit test equipment . It is called Heathkit test equipment matrix . Their site is not working for some reason .
but it had all the info on these older heathkit testers .
Would this crystal be for the marker ?
Heathkit called this unit a alignment generator .
I dont know if it has the crystal with it or not but for 10 bucks , I cant loose .

jshorva65
10-29-2007, 04:40 AM
Another collector recently mentioned that B&K produced a generator similar to the 415 which was set up for 21 MHz IF systems. The model number was unknown so I'm wondering if anyone else has seen this and remembers its model number. I use harmonics of the 10.7 MHz sweep and external markers with my 415 but doing so will also generate marker pips at the difference frequencies so it takes some practice to recognize which ones are correct. I use a dry-erase pen to place a "dot" on the plastic screen cover of my scope at the locations of the useful markers during setup. I borrowed the "dots" idea from an old TV service course textbook which suggested using a crayon or grease pencil.

Tube TV
10-29-2007, 04:57 AM
Thanks for the tip on using a dry erase pen on the oscilloscope .
I'll have to remember that one .
I was talking to the guy that is selling the unit to me and it does use a crystal , and he has it and has sent it with the unit .
It should be here in a few days .
I would amagine I should do a recap on it . and will have to clean the controls .
I think it was made in 1958 .
Would the crystal be for creating a marker frequency ?

jshorva65
10-29-2007, 06:03 AM
Thanks for the tip on using a dry erase pen on the oscilloscope .
I'll have to remember that one.
I was talking to the guy that is selling the unit to me and it does use a crystal , and he has it and has sent it with the unit .
It should be here in a few days .
I would amagine I should do a recap on it . and will have to clean the controls .
I think it was made in 1958 .
Would the crystal be for creating a marker frequency ?

A recap is definitely indicated here, as is a calibration check-up and recalibration if needed. The manual will generally specify a calibration tolerance. All of my test instruments get an annual check-up and recalibration if factory-specified tolerances aren't met. If it's an external crystal, then it's probably for a marker frequency. Most generators were shipped with a 4.5 or 10.7 MHz crystal and other frequencies were available from their Parts departments as accessories. Some use an internal crystal reference oscillator for checking calibration "on the fly" in between annual check-ups. When verifying or recalibrating, I use a modern solid-state (Elenco 9500) generator with built-in frequency counter as a reference.

Also, I highly recommend obtaining the manuals for ALL your test gear to perform check-ups and calibrations regularly. My B&K 707 tube tester had drifted somewhat and was showing Good tubes as marginal and marginal tubes were testing Bad. After obtaining the manual and following the procedures for setting the Balance, DC Bias and Signal Amplitude back to factory specs, I'm getting the accurate tube test results that were the reason for my buying a Dynamic Mutual Conductance tester in the first place. Also, beware of poor solder connections in 60's vintage gear using early PC board technology. My RCA WV-77E had issues with pin 7 of the 12AU7 and would intermittently "peg" the meter spontaneously. The fix was to unsolder and remove both tube sockets, clean each contact and PC trace, then reinsert and resolder the socket connections. The sockets were sitting up too high so the pins weren't protruding far enough through the board to make a secure joint. Thermal effects on the pins cause a hairline fracture at the joint and some pins had "pocket" joints. Pin 7 was the worst of them, and the "floating grid" condition it created would throw the circuit wildly off balance. It actually damaged the original 12AU7, which I needed to replace along with the solder joint fix. Basically, the zero-bias operation resulting from the floating grid "stripped" the cathode of the affected triode section and caused one side of the tube to go prematurely weak.