#1
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Eico Signal Generator
I got this little SG and a Heath VTVM at a yard sale some five years ago for I think a total of five bucks. The SG worked but had some hum in the signal, so I knew I had to recap it. Never got around to it but today because of cold rainy weather that keeps me from refinish work on the Firestone I'm working on in the Radio thread here, I finally did it.
The insides are pretty simple: dual electrolytic, little rectifier block, and a handful of paper caps. Here I've already clipped out the rectifier and it's sitting on top of the power xfrmr. I subbed a terminal strip and silicon diode for the rectifier and new caps all around. It fired right up and gave a smooth signal. The calibration was pretty close even after sitting around for years. I let it warm up a lot and then checked it by beating its frequency against known broadcast stations on the Firestone radio, which was also cooking away alongside it. I checked its operation at 455 Kc by beating the first harmonic against a 910 kc radio station. I'll get around to checking the higher frequencies against WWV later. Works fine and doesn't look bad for a $2.50 instrument!
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Reece Perfection is hard to reach with a screwdriver. |
#2
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I have a 324 also, and look forward to doing the same to it once I get my workshop set up later this year.
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#3
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Very nice I have an Eico 315 generator that needs an overhaul. I hope it works as well as this 324.
P.S. I see you have some of that Deft gloss I've been searching for |
#4
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These little SG's only take a couple of pleasant hours to overhaul. I was impressed how they mounted the oscillator tube upside down and cut a hole in the chassis to make a chimney effect for the heat: above the upside-down tube socket are a couple of temp compensated capacitors (I think) and it's all set up to stabilize operation and minimize drift.
I get my Deft at Lowe's: they should have it your area? If not they could order it for you for store pickup.
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Reece Perfection is hard to reach with a screwdriver. |
#5
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You got it for $2.50?
I just scored one of those at GW and it cost me 5 bucks! Mine needed a new electrolytic too, but seems otherwise fine, This winter I'll change the paper caps just to be safe, and I think I'll change the output connector to BNC since that fits almost everything else I have in the shop. Calibration on mine is pretty close too, but after recap and a nice long cook I'll touch it up. Nice, simple design, and seems pretty stable.
Does anyone have any thoughts on changing to a grounded AC cord? |
Audiokarma |
#6
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I didn't change to a grounded cord. I always use an isolation transformer on the set I'm working on but plug the SG right into the "raw" line. You don't always have to clip the SG shield lead to the set chassis, or if you need to, it can be through a cap. Most of the time just laying the output cable from the SG near the radio or near the IF tube when setting IF is enough, so SG-to-set grounding issues are under control. And I haven't used my SG in the shower, yet!
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Reece Perfection is hard to reach with a screwdriver. |
#7
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I have used my 324 for ages. Finally refurbed it last year. I think it will last forever.
I always check the output against a radio with a digital tuner. If your radio doesn't tune to a particular frequency, you can use a harmonic, as noted. Phil Nelson |
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