Photos, videos and docs of GrahamH, with the keywords: "analog"

CommsLinkTestSheet2

nobody@ipernity.com (GrahamH) — Sun, 26 Nov 2017 08:38:34 +0000

GrahamH has posted:

A two page test report for the transmission links for a two-way radio system. The links joined the track-side base stations and the control centre. The system is no longer in use. This is used for checking the links shown here: www.ipernity.com/doc/grahamh/24117033

E&M signalling over copper pairs in Australia was done using the 4W (1 pair each direction for the audio signal) circuit, ie no additional conductors. This is done in a similar manner to that used in feeding DC power to a condenser/electret microphone in a public address or studio sound system. The direct current for the signalling flows one way equally on both wires of a pair with the earth being used as the return conductor.

CommsLinkTestSheet1

nobody@ipernity.com (GrahamH) — Sun, 26 Nov 2017 08:38:28 +0000

GrahamH has posted:

U50dSanwa 2759

nobody@ipernity.com (GrahamH) — Fri, 29 Sep 2017 06:57:39 +0000

GrahamH has posted:

The multimeter from my teen years, a Sanwa U50d. It has the standard ranges for the era. Sensitivity is 50uA with 20K ohms for DC and 8K ohms for AC volts. See note.

U50dSanwa 2757

nobody@ipernity.com (GrahamH) — Fri, 29 Sep 2017 06:57:29 +0000

GrahamH has posted:

The multimeter from my teen years, a Sanwa U50d. It has the standard ranges for the era. Sensitivity is 50uA with 20K ohms for DC and 8K ohms for AC volts. See note.

TelecomsTestSheet

nobody@ipernity.com (GrahamH) — Tue, 14 Jul 2015 23:57:12 +0000

GrahamH has posted:

A test sheet used to record basic measurements on a 4 wire plus E & M circuit. For this project the functionality was mostly derived from either two pairs of copper wires or a 64K slot from a 2M PDH stream.

The links connected train radio base station controllers with the central control for the railway route.
See www.ipernity.com/doc/grahamh/24117033/in/group/873405

Jumper_colours0001

nobody@ipernity.com (GrahamH) — Sun, 30 Oct 2011 07:18:58 +0000

GrahamH has posted:

Old work. Colour coding for wire used at PMG / Telecom Australia sites to interconnect various controls and alarms which were part of analogue microwave radio links - 1960s to 1980s. IDF = intermediate distribution frame, a bank of terminals for cables from equipment which enable interconnections to made and varied as needed.