On Apr 1, 6:15*pm, wrote:
On Apr 1, 6:20*am, wrote:

*Letters on dials were originally to aid in dialing exchange names, eg
PEnnsylvania 6-5000 instead of 736-5000. *The US gradually
transitioned to "All Number Calling" by 1980.

I wrote a reply to this, but for some reason Google Groups won't allow
me to send it. *I'll try to send it as a reply just to you, which may
be better since it's quite long, and off-topic for this group.-

The above came through fine. *Not sure why google rejected your other
reply.

An email won't work. *This thread has already gone way off topic, so
it probably won't hurt to post it publicly. *Others may find it of
interest. *Maybe break it up into parts. *Thanks.

(Trains and telecommunications have many 'connections' in that they're
both common carriers, some of telephone technology is used for
signalling, and trains always have been heavy users of
telecommunications, including development of their own networks.)

Your post which I was trying to reply to is on Google Groups, in both
uk.railway and misc.transport.rail.americas, but does not appear in
either group in Giganews; I don't know what's going on.

The reply which I tried to send earlier was:

Somewhat different here. 0 was not used for the operator, at least
not in my time, the operator was 100. 0 was used for subscriber trunk
dialing. I think 0 may have been used for the operator in the early
days, but that was before my time. Normal GPO dials did not have the
word 'Operator' on them. 0 is still used to call the local operator
on PABX systems.

Leaving aside some very early dials, and special ones for pre-payment
callboxes, test instruments etc. there were four main GPO dials, the
10, 12, 21 and 54a. The 10 was used on candlesticks and early
Bakelite 'phones and was available in L (etter) and F (igure)
versions. The L dial plate, had only M and N on the 6 hole; O was on
the zero hole; there was no Q and no Z, Later dials added the Q in
the zero hole.

The 21 was introduced for the new thermoplastic 706 'phone in 1959.
This was basically our version of the 500. As with the 500 the
letters and figures were on a ring outside the fingerwheel, but this
ring was a separate part, fixed to the body of the 'phone by a metal
clip at the back, rather than an enlarged dial plate, as used by the
dial on the 500, Inside the finger holes there were arrowheads
pointing out to the numbers on the ring, rather than the dots which
the 500 used. This was known as the 'C' plate. The 'L' and 'C'
plates were also made for the 21 dial to enable it to be used as a
replacement for the 10 and 12 dials in older instruments. The 'L'
plate was also used, with a blank outer ring, after all-figure numbers
were introduced some time in the '60s. The 746, a slightly updated
version of the 706 was fitted with this arrangement. The 54a dial was
a cheaper, lightweight version of the 21, used the same dial plates
and finger wheels as the 21, but could not be used in the older
candlestick and bakelite instruments. The 54a lasted until the end of
the dial era. Many early puss button 'phones here were LD (pulse)
only, with ten buttons. Later models had twelve buttons, and were
DTMF or dual signaling.

These three sites should tell you jest about everything you want to
know about British telephones:

www.telephonesuk.co.uk

www.britishtelephones.com

www.samhallas.co.uk/telecomms.htm

Some of my collection can be seen he

http://www.classicrotaryphones.com/f...p?topic=1397.0

That's a 12F dial in the candlestick, which I've later replaced with
the correct 10F. The 232 Bakelite pyramid has a 10L, but you may not
be able to read the letters in the photographs. Towards the end of
the thread on page 5 there is a list of all of the American 'phones in
my collection, though I've since added a couple more. All work,
though several fave frequency ringers, and so won't ring.

Out ringing current is 75 V 25 Hz., rather than your 90 V 20 Hz. but
this is close enough for your straight line fingers to work here, and
ours will work over there. As for the dials, 10 pps is standard in
both places. The break ratio is different, I think ours is 66% and
yours is 60%, or have I got that the wrong way round? Anyway, again
it's close enough to work. Our ringing cadence of 0.4s on, 0.2s off,
0.4s on 2s off is also different to yours of course. Half way down
page two of this thread: http://www.classicrotaryphones.com/f...p?topic=1254.0
there's a post from me with a mp3 file of what it sounds like.

A comparison of out 706 with your 500: http://www.classicrotaryphones.com/f...hp?topic=804.0

A comparison of our 300 series Bakelite with your (older metal case)
302: http://www.classicrotaryphones.com/f...p?topic=1189.0

The 302 has since been fitted with some decent cloth cords and a four
prong plug.