Thanks for this video, that reminds me when i was young I rotate my AM radio to find the direction to the station in fact when the ferrite antenna points to the radio transmitter the AM signal became weak. Nowadays only a few stations transmit in SW or LW bands.
While admiring the wirewrap power bus, you ask “have you seen anything like that?” Yes, I have! I recognized it from inside a Nortern Telecom PBX from the early 70s. The same stuff was in the same way to distribute power to all of the card edge connectors on each shelf.
It's from 1977. 3 digit date codes were common back then so 731 is the 31st week of 1977. Some of the IC's had 4 digit date codes on them, some 3, most were from 77, saw a few from 76.
that is right ! thanks a lot for that comment, very important to know this , I should read up a bit more on this topic and explain it deeper in a video next time i see this format.
I don't think the LED Displays have built in controllers. They look like very early Displays made by Monsanto. I have some of them in my collection and they look similar. Today they are very rare!
Hi Thomas, nice Video ! I think you mean probably the TIL311 Style Hex Digital Displays with Logic. I used those extensively in the 80's Designing Displays. I liked those but they are Power Hungry, like everything from that Era. Btw, I came across a "RADIOMETER SE21 Regulated Power Supply" Service Manual, let me know if you want it, I have your Email from last Time. Cheers, Konstantin
the displays are HP bubble 5082-7405 I got the full manual and schematic for SE21A at peel dot dk see the radiometer section if your manual is another version, or better quality, please email me, so we can have it added to that page. and thanks a lot for writing and helping :-)
Thanks for this video, that reminds me when i was young I rotate my AM radio to find the direction to the station in fact when the ferrite antenna points to the radio transmitter the AM signal became weak. Nowadays only a few stations transmit in SW or LW bands.
While admiring the wirewrap power bus, you ask “have you seen anything like that?”
Yes, I have! I recognized it from inside a Nortern Telecom PBX from the early 70s. The same stuff was in the same way to distribute power to all of the card edge connectors on each shelf.
20:44 the top led tiny LED is turned on
At the same time, the CRT graticule lit up as well. (not the CRT though)
It's from 1977. 3 digit date codes were common back then so 731 is the 31st week of 1977. Some of the IC's had 4 digit date codes on them, some 3, most were from 77, saw a few from 76.
that is right ! thanks a lot for that comment, very important to know this , I should read up a bit more on this topic and explain it deeper in a video next time i see this format.
maybe an ultrasonic cleaner would help to clean the boards and remove any salt from under the chips?
I don't think the LED Displays have built in controllers.
They look like very early Displays made by Monsanto.
I have some of them in my collection and they look similar.
Today they are very rare!
the displays are HP bubble 5082-7405 so this model is 7 segments with no controller
Hi Thomas, nice Video ! I think you mean probably the TIL311 Style Hex Digital Displays with Logic. I used those extensively in the 80's Designing Displays. I liked those but they are Power Hungry, like everything from that Era.
Btw, I came across a "RADIOMETER SE21 Regulated Power Supply" Service Manual, let me know if you want it, I have your Email from last Time. Cheers, Konstantin
the displays are HP bubble 5082-7405
I got the full manual and schematic for SE21A at peel dot dk see the radiometer section
if your manual is another version, or better quality, please email me, so we can have it added to that page.
and thanks a lot for writing and helping :-)
10.8MHz, I guess this thing has a 3rd IF of 100KHz.