Telemetry systems - Page 1
Forum section: electronics / beginners

author: bonyz
author_rank: Contributor
timestamp: August 20, 2023, 11:14:59 pm
content: There is this product at ebay:https://www.ebay.com/itm/4015699671121. Why is there dial from 174Mhz to 216Mhz? Are you supposed to search for each signal?2. Is it compatible with all telemetry transmitter?3. For modern telemetry. How small is it now and does it have the same performance? The ebay one weight 18.5 Lbs.4. I don't know what year it is made.. but definitely before ICs were popular so it must have used transistors.5. I just need to know. If there was no transistors used. Could other components still make up the telemetry or radio?Thanks!

author: themadhippy
author_rank: Super Contributor
timestamp: August 21, 2023, 01:31:03 am
content: Quoteyou can make a radio out of a rusty razor blade

author: xrunner
author_rank: Super Contributor
timestamp: August 21, 2023, 01:36:52 am
content: Quote from: bonyz on August 20, 2023, 11:14:59 pmSo you can tune into the center channel frequency.QuoteNot likely since you would already know which frequency the system was going to use.

author: SmallCog
author_rank: Frequent Contributor
timestamp: August 21, 2023, 02:20:35 am
content: Given it was an existing receiver they had handy when they did this study in 1981 I'm guessing it's a pretty old bit of kithttps://link.springer.com/content/pdf/10.3758/BF03207940.pdfIn the world of environmental telemetry (this thing was medical) things have moved on quite a bit. With the proliferation of cellular services there is a plethora of equipment that goes straight to the internet with a built in cellular or NB-IoT modem.There are of course radio based systems still, with common technologies being spread spectrum UHF and LoRa WANIn the last few years low cost satellite telemetry has become increasingly common. It's arguably more economical for me to measure and telemeter non-intensive measurements (eg daily water level) via satellite than mucking around with cellular, even in urban environments using providers such as Myriota. I can basically deploy a little battery powered device that will measure and telemeter it's results over multiple years for naff-all money.I'd be surprised if this boat anchor on ebay was still "current" although I don't work in the bio/medical telemetry field.

author: bonyz
author_rank: Contributor
timestamp: August 21, 2023, 03:05:50 am
content: Quote from: SmallCog on August 21, 2023, 02:20:35 amIt existed already in 1981 so it was probably made in the 1970s or even 1960s. I heard transistors were very rare and expensive in 1960s. Is it possible to build it without using any transistor or vacuum tubes?Btw. Do you think the Apollo electronics or equipment that landed man on moon have any transistors or do they used vacuum tubes? With the recent crash of the Russian moon module. It seemed 1969 technology was very impressive.What is meant by IRIG Channel? Do we still use IRIG channel now?What present transmitter can still make use of it? I'm planning to buy it and peek if there was vaccum tubes inside but only if there are transmitters that can still use it.Quote

author: CaptDon
author_rank: Super Contributor
timestamp: August 21, 2023, 01:35:33 pm
content: It is probably transistor and early analog I.C. technology. Make a radio without tubes, transistors or I.C.'s?C'mon, you didn't really ask that question? It was built for BioMedical Telemetry, Cost Was No Object!!! Like when the military buys $1000.00 adjustable wrenches. Most of the biomedical transmitters I have worked on transmitted the lead Vii cardio signal using FM. The cardio signal shifted the carrier frequency. We even had a 'detector' in our laundry process to detect the transmitters which got wrapped up in the bed linens after it was removed from the patient. Ever tried a Google search for IRIG 7?

author: jmelson
author_rank: Super Contributor
timestamp: August 21, 2023, 02:52:47 pm
content: Quote from: bonyz on August 21, 2023, 03:05:50 amApollo was mostly discrete transistors except for the guidance computer, which used ICs. There likey was a traveling wave tube or Klystron in the communication and telemetry gear.QuoteIRIG is Inter-range Instrumentation Group. They defined time code and analog channel multiplexing schemes for missile test ranges back in the 1960's.Jon

author: CaptDon
author_rank: Super Contributor
timestamp: August 21, 2023, 10:34:55 pm
content: The frequency range of that receiver is interesting and correlates to older satellite downlink frequencies. Our BioMedical telemetry transmitters were in the mid 600Mhz range and had to be scrapped after the UHF television re-packing. Also our church wireless mic's had to be scrapped as they were also in the 600-700Mhz range. Those frequencies were 'auctioned off' by the F.C.C. and I think the money that was paid to buy those frequencies should have been paid out to anyone who had to scrap equipment, kind of like cash-for-clunkers trade-in. I think someone should have re-imbursed us for the gear we were forced to scrap!!! A giant F-U to the F.C.C. for not protecting consumers!!! Just like the hell hole of digital T.V.. Broadcasters reduced their power output so if you were in an analog fringe area then digital for that same channel was a for certain no-go!!! Fringe area reception for analog was tolerable with a snowy but watchable picture. With digital it is just one locked up video frame after another and garbled sound. Completely useless!!! The only good thing to come from digital T.V. is multiple channels on one carrier (If you have glitch-free reception).

author: bonyz
author_rank: Contributor
timestamp: August 23, 2023, 03:33:48 am
content: Quote from: CaptDon on August 21, 2023, 10:34:55 pmAre these 174Mhz to 214 Mhz still free? Are there telemetry instruments still using these frequencies? If not, then perhaps only a matching Bio-Sentry Telemetry Transmitter can make it work with their telemetry receiver described in original post?