Leader LSG-11 RF Output Connector Name - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

TonyDuell · 13th Mar 2023, 5:20 pm

I've never heard of an SO259 socket.

I thought that the connector often called a 'UHF plug/socket' was a PL259 plug and an SO239 socket.

DMcMahon · 13th Mar 2023, 11:50 pm

I do not know if SO259 actually exists but from Google searches several sites appear to be advertising it for sale.

David

DMcMahon · 14th Mar 2023, 11:50 am

Not yet found/sourced a replacement slide switch for the RF High/Low setting or a 5 Ohm resistor (or 4.7) for R10, so for the time being just replaced C4 and reconnected C4 & R9 (500 Ohm) to the RF output socket.

Replaced the twin flex mains cable with proper 3 core cable, connecting the chassis metalwork to earth (chassis metalwork was already connected to ground/power supply negative).

The twin flex entered the rear cover through a rubber grommet which had fallen apart. Fitted a new cable grommet, which required the hole to be enlarged (found my reamer this time). The cable also went through a hole in the chassis rear metalwork so fitted another grommet there also.

Powered up OK (for the first time) and it basiclaly appears to work on frequency ranges A to D, the sinewave signal is somewhat distorted (particualrly on the -ve peaks) and is heavily modulated (even when the Audio is switched to EXT).

Little if any signal seen on the top 2 frequency ranges E & F, this maybe due to limited bandwidth on my scope.

David

DMcMahon · 14th Mar 2023, 3:02 pm

Been having another quick look at the RF output, it appears to be quite variable/ not always the same, particulary in terms of the audio modulation.

Looking at the AF output I see that the 1kHz signal often is not there, it comes and goes with switching the audio modulation switch, often not returning when the switch is switched back to the 1kHz setting. A spray of Supersolve Super 10 has not helped. When present the 1kHz signal is 8V peak to peak (with AF In/Out pot set to max) clean and stable.

The 400Hz signal does not appear to work at all, just some low level RF breakthrough signal, signals on the EXT setting (with nothing connected externally) and on the XTAL setting (with no external crystal connected) are somewhat similar to whats on the 400Hz setting.

Will probably have to drop this for a while as too many other important things to do.

David

13th Mar 2023, 5:20 pm	#21
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,222	Re: Leader LSG-11 RF Output Connector Name I've never heard of an SO259 socket. I thought that the connector often called a 'UHF plug/socket' was a PL259 plug and an SO239 socket.

13th Mar 2023, 11:50 pm	#22
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,604	Re: Leader LSG-11 RF Output Connector Name I do not know if SO259 actually exists but from Google searches several sites appear to be advertising it for sale. David

14th Mar 2023, 11:50 am	#23
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,604	Re: Leader LSG-11 RF Output Connector Name Not yet found/sourced a replacement slide switch for the RF High/Low setting or a 5 Ohm resistor (or 4.7) for R10, so for the time being just replaced C4 and reconnected C4 & R9 (500 Ohm) to the RF output socket. Replaced the twin flex mains cable with proper 3 core cable, connecting the chassis metalwork to earth (chassis metalwork was already connected to ground/power supply negative). The twin flex entered the rear cover through a rubber grommet which had fallen apart. Fitted a new cable grommet, which required the hole to be enlarged (found my reamer this time). The cable also went through a hole in the chassis rear metalwork so fitted another grommet there also. Powered up OK (for the first time) and it basiclaly appears to work on frequency ranges A to D, the sinewave signal is somewhat distorted (particualrly on the -ve peaks) and is heavily modulated (even when the Audio is switched to EXT). Little if any signal seen on the top 2 frequency ranges E & F, this maybe due to limited bandwidth on my scope. David Attached Thumbnails Last edited by DMcMahon; 14th Mar 2023 at 12:11 pm.

14th Mar 2023, 3:02 pm	#24
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,604	Re: Leader LSG-11 RF Output Connector Name Been having another quick look at the RF output, it appears to be quite variable/ not always the same, particulary in terms of the audio modulation. Looking at the AF output I see that the 1kHz signal often is not there, it comes and goes with switching the audio modulation switch, often not returning when the switch is switched back to the 1kHz setting. A spray of Supersolve Super 10 has not helped. When present the 1kHz signal is 8V peak to peak (with AF In/Out pot set to max) clean and stable. The 400Hz signal does not appear to work at all, just some low level RF breakthrough signal, signals on the EXT setting (with nothing connected externally) and on the XTAL setting (with no external crystal connected) are somewhat similar to whats on the 400Hz setting. Will probably have to drop this for a while as too many other important things to do. David