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knight kit t 60

J

jer19541

Member
Dec 7, 2011
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i need help putting my t 60 back on air. i bought on on ebay, nice cond, said tested for power only. well replaced the electrolytics, doxit contro;ls, brought it up on a variac. all went well exept no transmit.manual says cr1 a crystal diode could be bad and replace. made me think it was the problem because it had been tampered with. is this a common problem in this transmitter?are there any other problems that would cause no transmit. (also i replaced the final tube) thanks, n4tbu.
 
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Kinda like the guy who asks why his radio won't transmit. Might be the mike, the radio or both. With no spare mike or spare radio to try, it's an open question.

The crystal must be ancient, leaving it as a possible failure. Have you tried listening on a receiver at the crystal frequency, just to see if a weak carrier leaks out of it? The oscillator circuit is a fairly brute-force arrangement. Even a weak crystal should oscillate, even if there's not enough drive to wake up the final tube.

Tubes are always a question even if they aren't quite 50 years old. Tube testers are not all created equal, but seeing the tubes pass muster that way might help.


Books on radio servicing written in the 40s, 50s, 60s would tell you the most-likely component to fail is an electrolytic capacitor. They have improved that technology a little since then, but you've already covered that ground. Next-most likely failure after that is a tube.

73
 
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nomadradio said:
Kinda like the guy who asks why his radio won't transmit. Might be the mike, the radio or both. With no spare mike or spare radio to try, it's an open question.

The crystal must be ancient, leaving it as a possible failure. Have you tried listening on a receiver at the crystal frequency, just to see if a weak carrier leaks out of it? The oscillator circuit is a fairly brute-force arrangement. Even a weak crystal should oscillate, even if there's not enough drive to wake up the final tube.

Tubes are always a question even if they aren't quite 50 years old. Tube testers are not all created equal, but seeing the tubes pass muster that way might help.


Books on radio servicing written in the 40s, 50s, 60s would tell you the most-likely component to fail is an electrolytic capacitor. They have improved that technology a little since then, but you've already covered that ground. Next-most likely failure after that is a tube.

73
Click to expand...
thank you, i bought these crystals on ebay . they worked in my hw 16. starting ro think i have 3 bad crystals. a good place to start.two of the three crystals were rebuilt, having new crystals put in . they look like walkie talkie crystals. also the 40 meter crystal (7046) took the cover off and looks oridginal. could i have 3 bad crystals?
 
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The T-60 was built to use a crystal type called "FT-243". Has two pins nearly a tenth of an inch diameter, a half inch apart. Inside is a so-called "pressure mount" that has a coil spring that presses a metal electrode against each side of the quartz element. It's a rectangle about 3/4" by 1/2".

Newer-type crystals that have the quartz soldered directly to mount wires inside may or may not have the power rating to survive that circuit. The quartz element in those is always smaller.

Never tried, don't know.

If a crystal works in another radio, that suggests it's okay.

Or was. Have you retried crystals that didn't work in the T60 in another radio SINCE trying the T60?

If a crystal that worked in another radio before the T60 won't work in the other radio now, that suggests it has been damaged.

One last question. Does the accessory socket have a 8-pin plug in it with pin 4 jumper-wired to pin 5?

Won't work without that.

73
 
nomadradio said:
The T-60 was built to use a crystal type called "FT-243". Has two pins nearly a tenth of an inch diameter, a half inch apart. Inside is a so-called "pressure mount" that has a coil spring that presses a metal electrode against each side of the quartz element. It's a rectangle about 3/4" by 1/2".

Newer-type crystals that have the quartz soldered directly to mount wires inside may or may not have the power rating to survive that circuit. The quartz element in those is always smaller.

Never tried, don't know.

If a crystal works in another radio, that suggests it's okay.

Or was. Have you retried crystals that didn't work in the T60 in another radio SINCE trying the T60?

If a crystal that worked in another radio before the T60 won't work in the other radio now, that suggests it has been damaged.

One last question. Does the accessory socket have a 8-pin plug in it with pin 4 jumper-wired to pin 5?
thank you so much for the information. mine dident come with the acc plug, so i jumped 4and 5 . and tuned up in a dummy load 40 watts clean tone. it works!!!..going to try 3535 tonite. again, thank you for helping me get back on the air...jerry watkins n4tbu.
Won't work without that.

73
Click to expand...
 
While not the same radio, my Viking Valiant works well with the small, newer style crystals. Just had to make an adapter to go from the octal connector, to the small socket.
 

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