Now for the rest of the crap.
The Farnell TM6 was listed as TESTED (yeah right!) but for £15 I was expecting to walk away with a meter movement and a bunch of parts to be honest. It's a 50KHz to 1.5GHz rated RF millivoltmeter which is good down to -50dBm and up to +20dBm apparently. Not bad!
I consulted the service manual in the middle of the field (smartphones FTW) and figured it was possible to fix it if it was indeed knackered so I thought what the hell and snapped it up for the asking price. It actually sort of works i.e. it reads something. But when throwing the roughly correct Marconi 2022E into it something was clearly amiss. All of the readings are low. After a few minutes of poking around this appears to be related to the probe interface. After cracking that open I found the culprit: the series resistor wasn't actually still soldered to the BNC port. Unfortunately this means that there is basically a very tiny capacitor in series with the probe tip. Bending the resistor around makes it work with some credible readings however the slug that you're supposed to solder it to is stuck down the end of the probe tube. I got bored here and decided to leave it for another day as my hands and my eyeballs have given up after all that driving today. Plus the HP is more interesting
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif)
Anyway some photos. Outside:
![](https://imgur.com/91jh5U4.jpg)
Top - power supply and meter calibration circuitry:
![](https://imgur.com/nfQkWfX.jpg)
Front end, chopper amplifier and RF front end calibration:
![](https://imgur.com/gYXPteC.jpg)
And finally the really interesting bit: the optical chopper. This uses LEDs unlike similar era HP stuff. Must have cost a fortune at the time as the chopper oscillator is driven via a metal can 741 and the LEDs are gold cased ones from the dark ages. Very sexy.
![](https://imgur.com/b8O9r9w.jpg)
Ignoring the two ARRL books I snagged, only to sell, I did pick up a bunch of parts to use in projects. I picture says a thousand words so here's a fiver of parts. I'm happy with that
![Smiley :)](https://www.eevblog.com/forum/Smileys/default/smiley.gif)
![](https://imgur.com/VRlu9dT.jpg)
Anyway both TE items entered the disinfect and repair queue now which will resume after I've moved.