HP 41C Video interface test. Howto?

[Dave Frederickson]

(07-12-2020 01:33 PM)Sylvain Cote Wrote:  

(07-12-2020 10:56 AM)tribidouille Wrote:  Side question: The antenna adapter is useless until you don't want to plug/unplug cables all the time isn't it?

It is necessary if you want to plug the 82163 TV output to your TV.
To my limited knowledge, the 82163A TV output has the big part of the RF modulator in it but it need the VHF adapter to finish the job.
I would assume that some old TV did had a VHF adapter in it with a RCA plug but I do not remember having seen that.
I have never opened an VHF adapter, but since it is passive, I would assume that it only contains basic components in it. (resistors, caps and coils)

The antenna switch is NOT needed with a TV with a coax antenna input. All it does is switch the input to the TV between the antenna input and the input from the 82163.

The output of both the analog monitor and the RF TV output is 75 ohms. If you want to connect the 82163 to the coax input on your TV all you need is one of these and a coax cable.
https://www.amazon.com/VCE-2-Pack-Coaxia...ef=sr_1_14

The U.S. 82163A version includes a switch adapter which apparently also contains a 75 ohm to 300 ohm matching transformer (balun) to connect to the twin-lead antenna input on vintage TV's.

The export 82163B version includes an adapter which I presume is a matching transformer similar to this one, but with an RCA jack.
https://www.amazon.com/RCA-VH54R-Matchin...ref=sr_1_4

Dave