11-12-2016, 02:13 PM
Terry,
I think my version of Ohm's Law was written for my particular college (Wray Castle) in 1958 when it opened as a radio training school. I joined in spring 1959. They may have thought up that Ohm's Law version themselves, or got it from a textbook - don't know!
Anyone trying to build practical radio receiver without any knowledge these days may well burn their headphones out
The first circuit I ever built, showed the headphones connected between the anode and HT positive. It came from a very old textbook (The HT was only 22.5V because that was the highest voltage batty I could afford). I knew nothing about matching, but in my case, it didn't matter, because my headphones (ex RAF surplus) were the standard 4,000 Ohm types, and worked fine. As headphones all seem to be low impedance these days, it may burn them out if they don't use a matching transformer!
I really wonder if any young people try building valve sets, or even transistor sets, these days. I have produced a few instructional downloads, but there is very little interest in them. Although one or two that did get them, had no trouble in getting them to work.
I would have liked to have written a practical radio construction book, but abandoned the idea because of a general lack of interest. Repairing valve radios is not much of a challenge for me, and I am not into cabinet restoration - only interested in the "works." I have hopes of finding an old valve radio embedded in the mud of the River Ribble, and if I did, I would retrieve it, and make it work again. In the 50s, I was often finding old radios in the river, and that is what sparked my interest in the first place!
We are the same age, apart from a few weeks!
Bob
I think my version of Ohm's Law was written for my particular college (Wray Castle) in 1958 when it opened as a radio training school. I joined in spring 1959. They may have thought up that Ohm's Law version themselves, or got it from a textbook - don't know!
Anyone trying to build practical radio receiver without any knowledge these days may well burn their headphones out
The first circuit I ever built, showed the headphones connected between the anode and HT positive. It came from a very old textbook (The HT was only 22.5V because that was the highest voltage batty I could afford). I knew nothing about matching, but in my case, it didn't matter, because my headphones (ex RAF surplus) were the standard 4,000 Ohm types, and worked fine. As headphones all seem to be low impedance these days, it may burn them out if they don't use a matching transformer! I really wonder if any young people try building valve sets, or even transistor sets, these days. I have produced a few instructional downloads, but there is very little interest in them. Although one or two that did get them, had no trouble in getting them to work.
I would have liked to have written a practical radio construction book, but abandoned the idea because of a general lack of interest. Repairing valve radios is not much of a challenge for me, and I am not into cabinet restoration - only interested in the "works." I have hopes of finding an old valve radio embedded in the mud of the River Ribble, and if I did, I would retrieve it, and make it work again. In the 50s, I was often finding old radios in the river, and that is what sparked my interest in the first place!
We are the same age, apart from a few weeks!
Bob
