During a quick search on Google I found this relevant link to a Liverpool Police History web site. If anyone can provide further information for Dot Holden please post a reply to this topic.
Steven R. Cole
29th December 2016
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The following text is an extract from Dot Holden's e-mail:
"I was recommended to contact you regarding my father, Edgar Menzies, who joined Liverpool Police in 1921 and founded their Police Radio Workshop. My Dad invented the first radio receiver for the Police pedal cycles moving on to making a two way radio system for use in a car. Dad owned the patents but transferred these to the Liverpool Police as he felt they had paid him to invent his designs and provided the necessary equipment. I wonder if your records hold any data about him and/or the Liverpool Police Radio Workshop?
My Dad had been a Radio Ham for many years before joining the Police, his call sign was G5MQ. I have attached some photos of Dad and his HAM radio equipment as well as some of his work in the Police Radio Workshop. He can also be seen in the picture of the car looking back at the camera."
PHOTOGRAPHS (from Dot Holden)
![Image](http://www.dtels.org/forum/images/Edgar%20Menzies%20in%20Workshop.jpg)
Sgt Edgar Menzies (G5MQ) in the Police Radio Workshop
![Image](http://www.dtels.org/forum/images/Edgar%20Menzies%20in%20Police%20Car.jpg)
Sgt Edgar Menzies in a Police Car
![Image](http://www.dtels.org/forum/images/Edgar%20Menzies%20G5MQ%20QSL%20Card.jpg)
Edgar Menzies (G5MQ) QSL Card dated 20th June 1927
![Image](http://www.dtels.org/forum/images/G5MQ%20Amateur%20Radio%20Station.jpg)
Edgar Menzies (G5MQ) Amateur Radio Station
![Image](http://www.dtels.org/forum/images/Evening%20Express%2022Jun44%20News%20Cutting.jpg)
Evening Express Press Cutting from 22nd June 1944