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Products => Test Equipment => Topic started by: GreyWoolfe on November 10, 2017, 10:22:00 pm

Title: Anyone know anything about this RF signal generator?
Post by: GreyWoolfe on November 10, 2017, 10:22:00 pm
This is an Electronics Measurements Corporation, New York, NY, RF signal generator.  My ham radio club received a rather large donation of equipment and this was in one of the boxes.  It does power on, the single tube glows (didn't check tube type) but it only puts out 60 Hz regardless of the setting.

Has anyone seen or owned one of these?  Maybe even have a schematic for it?  It defeats my Google Fu to find out anything on it.
Title: Re: Anyone know anything about this RF signal generator?
Post by: T3sl4co1l on November 11, 2017, 04:21:56 am
Sanity check first: replace the capacitors.

Likely the tube is a 12AU7 or 6SN7, or heck, even simpler than that, 6C4 or 6C5 or the like.  It can be checked on a tube tester (which, heh, your club probably has one, or does now).

The oscillator coils themselves should be fine, that's not an aging problem.  Do check for shorted caps, in case there are tin, zinc or silver metal whiskers growing out of plating or whatever.

Tim
Title: Re: Anyone know anything about this RF signal generator?
Post by: edpalmer42 on November 11, 2017, 04:45:26 am
http://antiqueradios.com/forums/viewtopic.php?t=90853 (http://antiqueradios.com/forums/viewtopic.php?t=90853) - schematic

https://www.youtube.com/watch?v=Uklg6tI9L24 (https://www.youtube.com/watch?v=Uklg6tI9L24) - troubleshooting

Title: Re: Anyone know anything about this RF signal generator?
Post by: GreyWoolfe on November 12, 2017, 12:39:51 am
Ed, thanks.  I found a link to the antique radio website and the link had a bunch of stuff but not the signal generator.  It seems it was a fairly cheap kit but it might be worth trying to bring it back to life.  There is only a couple of caps in it so it shouldn't take much money to fix up.
Title: Re: Anyone know anything about this RF signal generator?
Post by: edpalmer42 on November 12, 2017, 01:08:19 am
I noficed that yours has been modified.  The BNC jack definitely isn't original.  Watch out for more internal mods.

Ed
Title: Re: Anyone know anything about this RF signal generator?
Post by: GreyWoolfe on November 12, 2017, 01:39:27 am
So did I.  I am going to have to draw a better schematic than what I have been able to pull off the computer.  There is only the 1 40 uF capacitor.  I actually need 2 additional of the same value so I will have to hunt them down.
Title: Re: Anyone know anything about this RF signal generator?
Post by: georgd on November 12, 2017, 02:40:00 pm
At 38th minute o fthis video I saw some tools unknow for me:
https://image.prntscr.com/image/eb2HEyeCT7_CvZZ50VQSLA.png
What are these orange cakes?

Georg
Title: Re: Anyone know anything about this RF signal generator?
Post by: GreyWoolfe on November 12, 2017, 09:58:07 pm
At 38th minute o fthis video I saw some tools unknow for me:
https://image.prntscr.com/image/eb2HEyeCT7_CvZZ50VQSLA.png (https://image.prntscr.com/image/eb2HEyeCT7_CvZZ50VQSLA.png)
What are these orange cakes?

Georg

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