Nice repair of that biscuit warmer Mike. :-) It is crazy the heat these things produce. Thanks for sharing. I got to tear down my Tenma 72-5000 in the near future. Lost sensitivity for some reason.
No idea. This unit was giving to me from a friend that had picked it up in an estate sale. It is on the list to look at this week. Probably a bad diode of cap in the front end.
Hope not. Many years ago I built a Heathkit IM-2410 FC. Very nice bit of test gear. It got so you could not read any signal. The front end protection diodes was the issue. Very easy to troubleshoot that one. Hope this one has the same problem. This unit is a rebadged Tektronix CMC251
Very cool! I currently have a "Dick Smith 500MHz (no model #)" on the bench, it too has the same issue, turns on but nobody's home! I haven't yet had a chance to trace it out, just cracked it open...mine has 5 socketed IC's, so I'll check for chip creep, will replace the e-caps and check the very few parts it has inside. Just a clarification on your workflow, I know you automatically change out the e-caps as so do I, do you also automatically change out the tantalum capacitor? Is this a practice I should incorporate as well? Thanks! ~Jack
Not always but frequently. It really depends on what they installed. Tantalum caps are actually very reliable, however...... Some equipment manufacturers tend to use caps that have a voltage rating very close operating voltage. The downside of tantalum caps is when they fail they have one failure mode, a dead short. Can't count how many I have replaced in radios that exploded because they shorted out, sometimes taking other components with them. So I usually check their rating and replace them if they have a low voltage rating. Most radios operate on 13.8 volts and they install 16 volt tantalums. We all know there is going to be some ripple voltage coming out of the power supply not to mention line surges. They just run to close to the red line. When I replace them I'm installing them to upgrade operating voltage.
OK I can't find a manual for my FC-70 so does anyone know the frequency coverage & how much power can I run thru it? I am wanting to use it with a Siltronix 1011D & don't want to burn either of them up doing so.Thanks & 73
Cert and governing body for what? This is not a labratory counter. It's a two way radio inline frequency counter. There isn't a accredited labratory on the planet that would even let one of these pass through its door much less calibrate it. Radio operators use this type of counter to see what channel they are on. If you want a counter you can get a accredited calibration certificate for you need something a whole lot more precise than this type of counter. Something like the lab counter I'm using in this video that is referenced with a HP GPS time and frequency reference receiver.
Oh, yes, you can get a cert. In fact at all the test benches in a large international manufacturer where I worked, all equipment, required regular Cal certs. We also had ISO auditors that audited us to ensure we did this amongst other procedures. Even if you have another counter calibrated it can be used to calibrate the one you are repairing. Just show traceability under tools used.
@@robertdixon6536 There is no way any reputable calibration laboratory would even accept one of these past their front doors. Inline radio counters are notoriously unstable and inaccurate. They don't even have a TCXO. This thing probably has a uncertainty of over 1kHz. It is not a instrument, it is a radio toy at best. It's several orders of magnitude away from even considering it a counter that could have a certified calibration. Remember, this is NOT something you would use as a bench counter and anyone who thinks it's accurate enough to use as a lab counter seriously needs to find another line of work because they don't understand anything about metrology.
