1972 test equipment: Name that test equipment - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: August 24, 2019, 07:04:16 pm
content: This from a old 1972 documentary on ship salvaging. What is this for sending teletype over the air? I see the telephone on the top on some type of receiver thing and the big V shaped graph that probably has frequencies on it.Full screen :https://youtu.be/rfkJ1Q7cglE?t=160

author: amyk
author_rank: Super Contributor
timestamp: August 24, 2019, 08:43:20 pm
content: Please crop your images.I don't think that's "test equipment" per se, but some sort of marine instrumentation.

author: soldar
author_rank: Super Contributor
timestamp: August 24, 2019, 08:51:07 pm
content: Quote from: amyk on August 24, 2019, 08:43:20 pmSeconded.And the equipment looks like radio communications equipment.

author: Beamin
author_rank: Super Contributor
timestamp: August 25, 2019, 07:00:09 pm
content: Quote from: soldar on August 24, 2019, 08:51:07 pmI thought it was radio teletype maybe but long before my time.

author: duak
author_rank: Super Contributor
timestamp: August 25, 2019, 10:10:31 pm
content: Could the unit with a wedge dial be a Siemens Debeg E566 receiver?http://www.boatanchors.de/german_receivers/debeg_e566/debeg_e566.htmlhttps://www.staff.science.uu.nl/~tel00101/FotoAlbum/RadioCorner/Sets/Siem566.htmundhttps://www.staff.science.uu.nl/~tel00101/FotoAlbum/RadioCorner/Articles/Siemens566.htmI don't know anything more about these receivers and until today didn't know they even existed. It looks like it has a number of bands useful for marine and a minimal number of controls to make it easy to use.I fiddled with RTTY in the 70's and frequency stability is an important consideration. Unless you want to sit there continually tuning the receiver to optimize the reception.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 26, 2019, 12:21:42 am
content: Certainly looks like the Siemens receiver.They weren't "state of the art" in 1972, but working radio rooms had a lot of good older equipment in service for many years.Such a receiver could have been used for SSB R/T signals, AM, hand sent Morse Code, or Machine Telegraph (RTTY) using a Teleprinter machine at both ends of the link.The large object on the left is amost certainly a transmitter.The rectangular device with what looks like a LED readout on the top right, may be a more "state of the art" receiver, with the big old Siemens as the standby receiver, but the relative positions make it look like the old beast was still the main one.Some of the stuffmaybe test equipment, as radio rooms, especially on tugs are liable to be very small & cramped, so things go "wherever they can fit in".Re:- Stability for RTTY.It was common with land based HF ISB/SSB commercial links to transmit a reduced carrier which a PLL at the receiver could lock to, reducing the stability requirements at both ends.Hams didn't do that, but, then again, they didn't need their RTTY systems to run unattended for most of a day.The reduced carrier thing may have been done with large vessels, but I doubt it was done with smaller ones.From memory, there were special coding/modulation schemes to allow for error correction, which reduced the stability requirements.(basically "workarounds")

author: Beamin
author_rank: Super Contributor
timestamp: September 13, 2019, 09:37:38 pm
content: Quote from: duak on August 25, 2019, 10:10:31 pmI want one of those. Think you can find them at ham swaps?I wonder how big its present day equivalent is?