"Archon" wrote in message
news
On 9/22/2010 9:18 PM, Arfa Daily wrote:


"Jeff Layman" wrote in message
...
On 22/09/2010 17:39, N_Cook wrote:

Closer look and the cotton covering to the wiring between the output
heaters
is "perished", crumbling to dust, and needs replacing. Strange having
a load
of Mullard, Brimar and Z&I Aero valves to test

Z&I Aero!!! I haven't heard that name for over 40 years. That was when
their shop in Tottenham Court Road was worth visiting, followed by a
stroll to Proops, and then onto Lisle Street. Are there any surplus
places worth visiting today?

--

Jeff

I still have a Z&I Aero (Zaerix) glossy covered catalogue / data book in
near pristine condition. It has data on lovely old things like VCR97
'scope tubes, and has all the prices in pounds, shillings and pence ! Oh
those lovely old days of skiving off school for the day and jumping on
the train to London to go to Tottenham Court Road and Lisle Street. Into
Henry's Radio ... I bought my first 'hifi' amplifier in Proops.
snip
Arfa

I'm surprised you didn't build the "Texan amplifier" sold by Henry's,

http://www.angelfire.com/sd/paulkemble/sound8h.html

I must have built 10 of those for me and my mates, then spent many happy
hours replacing the unprotected output transistors! They did sound good
cranked up (with a good heatsink)!

JC

Oh, I did. I built probably three all told, and then a Mark 2 for a friend.
He's still got it I think. I'll ask next time I see him. That was a
Practically Witless project, designed by a couple of lads from Texas
Instruments just up the road from me in Bedford. I went to college with a
lad from the same department, but not directly involved in the design.

I used to build lots of projects from that mag. Like 'The Clubman'
transistorised HF receiver. Jackson Bros tuning gang with 6:1 epicyclic ball
reduction drive. Repanco and Denco coils. Remember those ? Different colour
plastic former for each function, and they plugged into B9A valve holders. I
also built an audio amp that used those output transistors that looked like
TO3s that had shrunk in the wash. Can't remember the type numbers of them
now. I still have that amp under the bench in the workshop, and it still
worked last time I put it on. I also built the famous PW frequency counter
that used those seven segment filament displays, and a cartload of 74 series
TTL. Don't build too much any more, except bits of special purpose test
equipment to make my life easier.

Arfa