Hey What is this old school rusty Leader thing? - Page 1
Forum section: electronics / testgear

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:56:57 am
content: Got this one cheap but not sure what use I can make of it? Any comments and information all welcome and appreciated.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 19, 2020, 10:40:07 am
content: video pattern generator ? show us the back panel

author: srb1954
author_rank: Super Contributor
timestamp: October 19, 2020, 11:25:40 am
content: It's part of a sweep oscillator/marker generator. It may be just a modulation plug-in intended to be used within a main frame containing power supplies and other support circuitry.My guess is that it has been customised for use in a production test environment for aligning IF strips in old analog TV sets or similar. The minimal number of front panel controls suggests that it was intended for use by semi-skilled production line personnel.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:28:01 pm
content: I did try to add more photos but was restricted by the size of attachment. Now more

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:33:07 pm
content: By the way, I had an initial dedust and derust and plugged and turned it on, it seamed to work. The top left meter came to its centre point of its scale, the led lit on, and there was a nice modulated hi frequency signal detected from the front terminal. And the modulation can be switched off.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:35:39 pm
content: Quote from: srb1954 on October 19, 2020, 11:25:40 amI think this is a very sensible and wise guess.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:36:54 pm
content: Another clearer photo of the front panel.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 19, 2020, 06:40:08 pm
content: I guess this might be used as a signal generator, though really very limited, with and without the low frequency modulation.This seems to come at the right time because I’m now interested in ham and radio stuff?

author: srb1954
author_rank: Super Contributor
timestamp: October 19, 2020, 08:48:55 pm
content: Quote from: max.wwwang on October 19, 2020, 06:28:01 pmThe rear panel connections indicate that the unit is intended to connect to a scope showing the amplitude vs frequency response of the IF strip being aligned. At the fixed marker frequencies there will be a pip or bright spot on the trace identifying critical frequencies in the alignment process.

author: free_electron
author_rank: Super Contributor
timestamp: October 20, 2020, 01:32:14 am
content: IF alignment tool. it sweeps from a start to a stop frequency. you hook up the h and v of a scope. ( basically scope in x/y mode ) . when it passes the set frequencies it generates a 'spot' on the oscilloscope . This is basically a bandpass analyser. You send the signal this generator makes through the filter under test. So you get a bode plot. the spot is generated by temporarily sending the output signal very high and very low ( so you get a vertical line there )the operator can tune the corners of the bandpass filter so they align with the two spots.Old school TV filter kerjiggery.

author: max.wwwang
author_rank: Frequent Contributor
timestamp: October 20, 2020, 03:21:14 am
content: Quote from: free_electron on October 20, 2020, 01:32:14 amThanks. Will test it with x/y mode of oscilloscope.Any more use of it nowadays, or potential of modification?