BBC AC Test Set EP14/1P

[Nymrod121]

Evening everyone,

I acquired this back in January 2016 from Chris in Manchester [reddish75] - thank you, Chris

I've done a bit of a restoration and overhaul on this - *lots* of helpful advice and support from forum members!

Details / acknowledgements as follows:

Mains transformer re-wound - thank you, Ed [Ed Dinning];

Auxiliary DC supply cable harness made up using Painton/McMurdo 7-way socket to 3-pin XLR chassis plug - thank you, Bill [AC/HL] and Roger [G3VKM_Roger];

Supply rails brought back into specification - several AOT resistors had to be changed and I made up an extender card to help with this using Veroboard and an ISEP 25- way plug from a discarded experimental circuit board - thank you, John [John B-S]);

Supply rail check / 'Cal Osc Set Level' metering push-button assembly dismantled, cleaned, silver-dipped to restore reliable contacts, re-assembled;

Output level calibrated against Fluke handheld DMM (60Hz, 0dBu => 0.775v r.m.s.); input metering boards re-aligned (Amp-Det & Test Programme Meter circuits);

Main meter needle binding against inside of faceplate - 'persuaded back' towards the scale plate (but oh-so-carefully );

Carrying case, lid and handle: shotblasted / lid corners repaired (welded) then all metalwork powdercoated in hammered silver;

DZUS toggle latches replaced - thank you, Goldie99 ...

The photos tell some of the story (I've used what I hope are meaningful file-names).

Best wishes
Guy

[Nymrod121]

Some more pics of the equipment in action.

Best wishes
Guy

[fetteler]

Guy,

That is a lovely job - well done!

I have one of these testers that I have brought back to everyday working condition but it is nowhere near the beautiful restoration you have achieved.

All the best,
Steve.

[Nymrod121]

Hi Steve - thank you for your kind compliments. They're a lovely beast and phrases referring to small external buildings come to mind

I've a rack-mounted version (obtained from the "TVC Final Clearance" disposal in early 2015) that also needs attention.

On this one, I suspect a leaky capacitor in the input level measurement '0.5dB' step attenuator assembly; as found, this was presenting ~3.7v DC to Board 3, thereby forcing the meter needle to right-hand f.s.d.

As a work-around, I've fitted a 0.1uF capacitor in series with Board 3 input to block this DC component. A result of this is the measurement accuracy becomes degraded at low frequencies so I'm planning on removing the input step attenuator assembly and changing all the C's - a complicated & fiddly job, but there's the fun of it ...

Cheers
Guy

[unixmanuk]

Those pics bring back memories from days long ago at Wood Norton, and latterly at TVC.

I remember everyone having one on their desk on the course whilst going through the setup procedures.... great fun!

Cheers,

[mhennessy]

There are still some left at Wood Norton, but not many. Perhaps only 2 or 3... Lovely though they are, they come from the 600 ohm world, and that's far too confusing for trainees today

We also have a couple of ME2/5s (and I have one at home), but in many ways, the 2/5 was a step back. But a bit easier to carry about!

I don't think I've seen one of those cases before - I bet it adds to the mass

Well done on an excellent restoration! It looks like a new one

[Nymrod121]

Thank you all for your feedback and kind comments

John: the other one I have was originally fitted in a "MADI test trolley" comprising a Probel coder, transcoder & decoder set, along with Musa and B-gauge jackfields and a Canford Audio monitoring amplifier ... it was part of the Peaker Pattinson 'final TVC clearance' auction disposal in Jan-Feb 2015 ... maybe you can recall seeing it at TVC?

Mark: the ally transit case was quite common in T & SCPD's (Transmitter and Capital Projects Departments, for the benefit of non-Beeb folks) and the mobile TMTs (Transmitter Maintenance Teams). The one I've just refurbished has an SCPD asset label (albeit mucky /scratched and for which I'm going to try and get a Trafolyte replacement some time in the future).
You're right about the weight of it. Over the last week or so I've felt a bit like the Cadbury's Smash robot with the extending spring arms
Cheers
Guy

[fetteler]

Mine's in that very same case, it's ex Radio OBs London. We also had a couple like it in Tel OBs. Being mad from aluminium it's not as bad as you would expect for weight.

Good luck Guy with the cap replacement, I'm sure it will be fine, and, yes, well worth the trouble... sorry fun!!!

Cheers,
Steve.