Golborne Vintage Radio

Full Version: Farnell TM8
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Wonderful.

I've had a TM8 for many years.

Turned it on today: dead as a dodo.

Changed the fuse & powered up via The Big Green Light Box (fortunately).

It's a royal pain to dismantle and eventually once in bits turned out to be a shorted 1000uF reservoir capacitor.

Worked ok in bits.

Reassembled with difficulty and lo! suddenly it's very odd.

And then the Big Green Light Box lit up in approved fashion.

No idea what's wrong with the TM8 now, but I'd wager the mains transformer is shorted.

There's a HP3586C that would do the job I was attempting, but there's even less chance of that working than of fixing the TM8.

Also the 3586 is too big & heavy to shift.

Ho hum.
Live connecting wire in the psu pinched against something or other.

Found the easy way to mantle & dismantle the thing.

Happier now.

As it turns out I bought it in 1998.
For those of us unfamiliar with this instrument: https://archive.org/details/manualsplus_00488
And just think: I paid actual money for an actual copy of that manual. Smile Rather a lot of years ago.

Oh, and I had a spare part once it was all back together again.

No idea where it goes.

By the way the HP3586C is a selective level meter.
https://www.ppauctions.com/archived-lots...ivoltmeter

Having both RF and True RMS makes it a bit special. Usually you can have one but not both. My VTVM works to 150 MHz, but either measures peak or assumed sinewave for RMS voltages.

I've a DVM that does true RMS, but I doubt even up to the limit of audio.

My spectrum analyser can measure μV up to 1.5 GHz, but not true RMS. Peak and maybe something called "Average RMS". Can do zero span.
I've also a digital scope (with missing logic analyser pod) that can measure , but only peak and average up to 100 MHz, so less good than the old VTVM.
I like the Farnell Instruments kit.

I have several power supplies, voltmeters and signal generators.

Especially good since most of it doesn't have microcontrollers embedded inside.