UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Vintage Engr · 17th Nov 2017, 11:40 am

Thanks,
I guess I'm now expecting too much from the Philips.

That said, as I previously mentioned I have other TV pattern generators that , on the same scope, with BW limited to 20Mhz, are perfectly clean. I do appreciate what you are saying regarding the tilt etc. But, when displayed on the Hantek, (when it worked 3 weeks ago) which has a TV line selector, or using an old BBC line selector, the problem is still there on a white pattern (no burst), on all lines.

In the early 70's I used to work on Philips broadcast equipment, it was quite early stuff, the SPG / bar gen was made up of several separate rack-mount units, with gates & flip-flops in large IC-like modules (with discrete transistors inside!), rather like Elliot mini-logs.
Even with this, the colour bar signal was clean, so they could have done better in the PM5519. Like you say, the mixing of analogue & digital on the same power supplies isn't a good idea. I used to have a couple of PM5509's & they were cleaner than this one.

I'm going to call a temporary halt on it today, as I must get back to the Hantek scope, & either fix it or send it back to China, before the Christmas rush.

Before I do, just one further question, related to the intercarrier sound on the PM5519.

I was going to try & convert the G version back to I. Although on my unit, there is an extra PCB that encodes the Zweiton stereo sound, - on mono, it appears to be o.k. with 5.5 MHz intercarrier. I have checked it on a multi-standard TV. All I require to do, is change the intercarrier to 6MHz.
According to the very early manual copy I have, it is just two solder links that need to be altered, on unit 10, the main pcb, adjacent to the sound modulator unit.

The manual states: Close solder joint I, Open solder joint H.

There does not appear to be a solder joint I, there is however one marked J. The PCB layout that another member kindly uploaded, doesn't show solder joint 'I' either.

This might just be a typo in the manual I have. could I ask if it is the same in your manual, or is it indeed 'J'?

Thanks.

17th Nov 2017, 11:40 am	#39
Vintage Engr Heptode Join Date: Jan 2008 Location: Shrewsbury, Shropshire, UK. Posts: 847	Re: Philips PM5519 Service info Thanks, I guess I'm now expecting too much from the Philips. That said, as I previously mentioned I have other TV pattern generators that , on the same scope, with BW limited to 20Mhz, are perfectly clean. I do appreciate what you are saying regarding the tilt etc. But, when displayed on the Hantek, (when it worked 3 weeks ago) which has a TV line selector, or using an old BBC line selector, the problem is still there on a white pattern (no burst), on all lines. In the early 70's I used to work on Philips broadcast equipment, it was quite early stuff, the SPG / bar gen was made up of several separate rack-mount units, with gates & flip-flops in large IC-like modules (with discrete transistors inside!), rather like Elliot mini-logs. Even with this, the colour bar signal was clean, so they could have done better in the PM5519. Like you say, the mixing of analogue & digital on the same power supplies isn't a good idea. I used to have a couple of PM5509's & they were cleaner than this one. I'm going to call a temporary halt on it today, as I must get back to the Hantek scope, & either fix it or send it back to China, before the Christmas rush. Before I do, just one further question, related to the intercarrier sound on the PM5519. I was going to try & convert the G version back to I. Although on my unit, there is an extra PCB that encodes the Zweiton stereo sound, - on mono, it appears to be o.k. with 5.5 MHz intercarrier. I have checked it on a multi-standard TV. All I require to do, is change the intercarrier to 6MHz. According to the very early manual copy I have, it is just two solder links that need to be altered, on unit 10, the main pcb, adjacent to the sound modulator unit. The manual states: Close solder joint I, Open solder joint H. There does not appear to be a solder joint I, there is however one marked J. The PCB layout that another member kindly uploaded, doesn't show solder joint 'I' either. This might just be a typo in the manual I have. could I ask if it is the same in your manual, or is it indeed 'J'? Thanks.