|‘Technical Shorts’ is a series of (fairly) short articles written by Gerry O'Hara, a CVRS Director and vintage radio enthusiast, each focusing on a technical issue of relevance in repairing, restoring or using Eddystone valve radios. However, much of the content is also applicable to non-Eddystone valve receivers. The articles are the author’s personal opinion, based on his experience and are meant to be of interest or help to the novice or hobbyist – they are not meant to be a definitive or exhaustive treatise on the topic under discussion….
References are provided for those wishing to explore the subjects discussed in more depth. The author encourages feedback and discussion on any topic covered through the CVRS forum.
Oscilloscopes in Radio Servicing
When I was a lad, I always wanted an oscilloscope (‘scope) – they just looked so cool, at least in an electro-geeky sort of way – all those knobs to twiddle, sockets to plug things into, buttons to push, technical sounding markings on the panel and, most importantly, a real-time display that apparently showed exactly what was happening in the piece of kit you were fixing such that diagnosing the most complicated problem would become a doddle… or so I thought. I eventually bought my first ‘scope in the 1970’s – a rack-mounted, single-trace Telequipment valve job from ‘AH Supplies’ in Sheffield (model ‘S32R’ I think) – for the princely sum of £10. After fixing the HT circuit (new EHT rectifiers and caps – replacements supplied, along with a schematic gratis by Telequipment, together with a nice letter – I was most impressed!) and a faulty time-base (leaky capacitors), I had a workshop ‘scope that I could finally cut my teeth on. Admittedly, it was a bit limited in terms of bandwidth and it was not the most stable of ‘scopes, however, it did me proud for my outlay of £10 for many years and was only disposed-of when I ....
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