Anybody else using a Fairchild Thermo Stylus? Need photo

[Deke Dickerson]

If anyone else on the forum is using a Fairchild Thermo Stylus, I would really appreciate an underside photo of a functioning unit.

I bought one off of eBay a couple years ago and just now getting to the point of needing to get it up and running. I took the back off for the first time and discovered, that although all the components were there, someone had annoyingly gone in and "clipped wires." Perhaps the transformer is bad, not sure why they did that, but I need to know where these wires go so I can get the unit working.

Here are photos of mine. If anybody else can help I would sure appreciate a photo.

Deke

[Deke Dickerson]

Hmmm, trying again to post the photo links:

https://flic.kr/p/2gEHNJV

https://flic.kr/p/2gEHNKM

[markrob]

Hi,

From the photos, the wiring looks to be:

Stylus Heater Schematic.jpg

Since this may have been done for a reason, I would do the following

1. Check that the power switch is working with an ohmmeter.
2. To determine if the value of the secondary transformer voltage, see if there is still a pilot lamp present. If so remove and look at the part number of the lamp. For example a #47 is a commonly used lamp and runs on 6.3 Vac. Also see if you can get a part number for the meter and look up how to change the lamp. Checking that may also help confirm the expected voltage.
3. Reconnect the AC power cord to the switch and transformer primary and check the secondary voltage with an AC voltmeter. If this matches the value you obtained in step 2 then connect the remaining wires. If not, you may need a new transformer.
4. Use a 2-4 ohm 5 watt resistor to stand in for the stylus heater and connect it to the output. Power on the unit and see if you can adjust the rheostat to get the meter needle to indicate a reasonable operating range.
5. If the meter does not seem to function, it may be bad. To test this, jumper it out of the circuit and read the AC voltage across the dummy load resistor. It should vary with the rheostat to a max of around 2-5 Volts

Hope this helps. Let me know if you need more clarification.

Mark

[Deke Dickerson]

Thanks Mark!

Much appreciated. This is basically what I thought as well, I just didn't want to hook it up to AC unless I was sure.

But I think I can safely hook it up the way you've described, and check it along the way to figure out if there are any defective items.

My guess is that if they clipped wires it's probably because the transformer is bad, not for any other reason, but I'll figure it out. Thank you!

Deke

[markrob]

Hi,

Let us know what you find. I'm guessing its either a 12.6 or 6.3 volt filament transformer and should be easy to source.

Mark