PMG Shed Find.

[goodwoody]

Groovers,
In the hay shed I discovered an old PMG wall phone in very good original finish. This used to be connected to another phone between 2 dairies on adjacent farms. What my concerns is, as you can see is the modern wire/cable from the ear peice to the phone. Does anyone have any info on the correct wire that was used, either picture, real or written. I hope someone has the knowledge and possibly 1/2 a metre of the desired wire available for purchase or swap? regards Damien.

[dabbler]

No pic showing Damien.

[goodwoody]

Fixing now. The centre picture youcan see the white plastic wire, This is the one I am wanting to replace. Also, what is the large space at the bottom for? Was there a battery present at some time? Damien.

[dabbler]

I have several different Ericcsons in storage, with various cabinet shapes and cosmetic differences. I have never looked but imagine the wiring is identical. If know one else comes up with info, I need to photograph them for family, so I will be able to check in a week or so.

As for yours, it does look in good nick. The original wiring would have been a heavier gauge and presumably a different resistance to modern cable. To my knowledge they never had any batteries fitted and relied on the hand-cranked dynamo for transmission power. The cabinet was generic across several designed uses as far as I know. I have one designed as an office switchboard. It's cabinet is much the same but with extension sockets and wiring in the bottom section.

[dabbler]

I need to correct my comment on batteries. A friend just sent me this link.
http://www.telephonetalk.com.au/index.htm

There are several images showing batteries in the "Ericson" section. As soon as I saw them I realised they looked familiar so I must have seen them before and dementia is setting in.

There are links to other websites on this site too.

[goodwoody]

Thanks Dabbler , the link is very helpfull. I didn't realise that phones were collectable and that expensive. Damien.

[Pac man]

From my old man who is ex PMG:

The original cord is a receiver cord, two conductor made by Bly manufacturing in Moorebank. Original cable was silk and cotton covered for this model. Later ones were plastic. Model of the phone was a magneto wall handset (MWH) and the hand generator was mounted separately from the phone. Battery supply consisted of 2 x 1.5volt dry cells for each phone that go in the space at the bottom. The ends of the cord had spade connections that went under the screw.

He said try eBay for the cable or some antique phone collector. The Telstra phone museum in Bankstown NSW may have some info for you. Alternatively the cotton covered 240 cable could be used just using 2 wires.

Dad bought 4 of these for 50 cents each in 1967. He no longer has them.

[goodwoody]

Thanks PacMan, The phone is purely for cosmetic value on a wall so I will see the local sparky to see if he can source any of the cloth covered wire. Damien.

[Pac man]

No probs. it was a good opportunity for him to share his knowledge . I know it made him happy to do it.

[NCArcher]

It's not every day you get to use some of that knowledge you've acquired over many years. Good on ya Mr Crowe senior. I used to know lots of stuff like that but I had to forget it all because I needed the memory space for PINs and Passwords :doh:

Your best bet for the cable would be a lighting shop

[malb]

Phones for manual exchanges used a granulated carbon microphone, and the batteries were to power them. Effectively the microphone is a sound controlled variable resistor, two 1.5V batteries in series with the variable resistance mic gives variable current in the line feeding to the earpiece. The magneto generated a medium voltage AC signal that went down the wire to release a shutter relay at the exchange, to signify to the operator that you needed their attention to make a call. The exchange sent a similar medium voltage signal back to the phone to activate the ringer to advise an incoming call.

The 1.5V batteries used are big, about 75mm diameter by 200 high with two brass studs and finger nuts, one at the centre and one near the edge. They were used into the seventies to heat glowplugs in model engines for cars and boats, but as the rural phone network was automated, the batteries became scarce because the major market (PMG) dissolved.

Rotary dialer and the early (Telecom monopoly era) push button phones also used carbon microphones, but 48V DC is superimposed on the cables from the exchange to premises and this was used to power the microphone and limited electronics in the phone. When the market was opened to third party phones, there was a general tendency to migrate to small condenser microphones in the handset, and a substantial increase in the electronics in the phone.

Because the carbon granules in the older microphones could compact over time, the sound quality could become muffled and difficult to understand. The standard solution to this was for the other party in the conversation to advise the one with the muffled voice to belt the phone, then move the handset away from their ear. A quick rap of the microphone end of the handpiece on a table top or phone book would restore the microphone performance for a year or more. This action is occasionally seen in old films etc.

[A Duke]

Hi,
I seem to remember that size battery being called "Igniter Batteries".
Did they have 'party lines' in Australia when those phones were in use?
Regards

[Wrongwayfirst]

Hi,
I seem to remember that size battery being called "Igniter Batteries".
Did they have 'party lines' in Australia when those phones were in use?
Regards
Uncle joe up on the farm out of balranald was "two short and one long ring" as his phone number. Yes it was a party line and that was how the gossip travelled around in the early 70's. The phone was up on the wall way to high for me to reach(I'm 6'8" now so it was a very long time ago:U)

[gyropilot]

If you are having problems with the fabric cord, try an iron cord. A lot of them are fabric, and work great. (Find a thin cord, and remove one of the 3 wires if you need it even thinner)
Nostalgia for sure, I haven't fixed one of these phones for years! and the advice of banging the mic to dislodge the carbon granules works great.

Cheers


Geoff

[JohnQ]

There is also a Telstra Museum at Clayfield, north of Brisbane. Check the net to see which days they are open. Bankstown is open Tuesday & Wednesdays only.

JohnQ

[Mobyturns]

http://www.telstra.com.au/abouttelstra/company-overview/history/telstra-museums/ will put you in touch with an old tech who can assist with the knowledge aspect. There are also many historical villages and smaller unofficial "Telstra" museums about in the larger centres - Townsville had one.