PYE PMR in Northern Ireland - UK Vintage Radio Repair and Restoration Discussion Forum

TALKINGWITHPYE · 28th Nov 2019, 12:26 pm

Hello from Dave, I have come accross some very interesting posts from PMR engineers in England. I was also a PYE engineer in Belfast. One day we got a call from a hospital telling us that their radio system had failed. We went to the repeater site where I found a broken window, the receiver of the f27 switched off and a golf ball beside said f27. Someone on the golf course had a Wild shot me thinks.

Another strange one was when I was asked by my line manager about my high frequency hearing. I was sent to a mobile in a quarry where the driver was complaining of a constant noise in the cab. A colleague had been earlier but found no problem, but I did. Before I reached the vehicle I heard a high pitched whistle. It was the voltage dropper used with the m290. The whistle was the inverter oscillator.

Graham G3ZVT · 28th Nov 2019, 2:21 pm

Magnetostriction.
This was a well known issue in the TV repair business too.
When I started in the trade I could tell if the TV in the customers room was on 625 or 405 lines before I even saw the set, now I have no perception of even 405 line frequency (10,125Hz)
It was no good to keep sending a tech with cloth ears to a young customer who was slowly being driven insane by her television.

Sometimes the level was normal, and little could be done, but with many colour sets some of the inductors in the east-west correction circuits etc. were well known for singing away, and could be damped with a good squirt of RS multipurpose adhesive.

28th Nov 2019, 12:26 pm	#1
TALKINGWITHPYE Pentode Join Date: Oct 2018 Location: Carrickfergus, County Antrim, Northern Ireland, UK. Posts: 126	PYE PMR in Northern Ireland Hello from Dave, I have come accross some very interesting posts from PMR engineers in England. I was also a PYE engineer in Belfast. One day we got a call from a hospital telling us that their radio system had failed. We went to the repeater site where I found a broken window, the receiver of the f27 switched off and a golf ball beside said f27. Someone on the golf course had a Wild shot me thinks. Another strange one was when I was asked by my line manager about my high frequency hearing. I was sent to a mobile in a quarry where the driver was complaining of a constant noise in the cab. A colleague had been earlier but found no problem, but I did. Before I reached the vehicle I heard a high pitched whistle. It was the voltage dropper used with the m290. The whistle was the inverter oscillator.

28th Nov 2019, 2:21 pm	#2
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,710	Re: PYE PMR in Northern Ireland Magnetostriction. This was a well known issue in the TV repair business too. When I started in the trade I could tell if the TV in the customers room was on 625 or 405 lines before I even saw the set, now I have no perception of even 405 line frequency (10,125Hz) It was no good to keep sending a tech with cloth ears to a young customer who was slowly being driven insane by her television. Sometimes the level was normal, and little could be done, but with many colour sets some of the inductors in the east-west correction circuits etc. were well known for singing away, and could be damped with a good squirt of RS multipurpose adhesive. __________________ -- Graham. G3ZVT