Hi,
I have a 1954 HMV Radiogram.
When I first got my hands on it, it hadn't been turned on for a very long time and the power cable had been cut off. It has an external earth screw and a neutral and live wire which had been cut. I wired a mains lead, screwing the earth to the external earth screw and then connected the neutral and live wire to the mains lead. When I plugged it in everything powered up and all the lights came on. The radio function is all working fine (but on a high volume) and I have managed to tune it in to a couple of radio stations on MW. As for the record player, I turn the knob from the radio settings to 'G' which stands for gramophone which is the record player. When I press the start button, the platter spins around at the correct speed and the stylus automatically moves over the platter and lowers itself onto the vinyl record. But you cannot hear it at all.
After further inspection, I found that the two wires leading out of the record player inside the unit had broke off from the connector which slots in to a part in the record player. I soldered the wires back on to the connector and then powered it up. I put a record on the platter and press the start button and now, when you turn the volume up to max volume, you can very faintly and quietly hear the record playing through the speaker.
I then turn to the valves. It has 4 Marconi valves in it: N78, U709, DH77, N78.
One of the N78's was a bit dimmer and didn't get as hot as the other N78.
Because the N78 valves are the same I swapped them around, after doing that there was no sound from the record player on a high volume. So I figured that one of the N78 valves must me broken. I found out that the N78 valve that is not working was the one that was dimmer and not as hot. So, I ordered 2 replacement Marconi N78 valves which had been tested.
After I fitted the 2 new N78 valves, I plug it in and turn it on and the radio is louder on a lower volume and sounds very crackly and distorted.
I switch to the record player setting and test the record player but I cannot hear anything at all now even on max volume, I can only hear the speaker buzzing. However when I touch the needle, there is a very loud buzzing noise coming through the speaker.
In conclusion, the stylus is picking up the sound but it seems that it hasn't been amplified enough.
There is a small valve (DH77) which is the pre amp valve. I have not replaced that valve but maybe I should as it is 70 years old.
The U709 valve is larger than all the others and I think that is still working fine because when I remove it the radio doesn't do a thing.
Also, It has two removable styluses. One for 78's and another for 33's and 45's. The needle in the stylus that plays 33's and 45's broke so I am using the stylus meant for 78's on playing the records. I do not have any 78's but it does play the record fine be
Any ideas to what the problem is and what I should do next. I would love to be able to see it playing records again.
Thanks Zach.
I have a 1954 HMV Radiogram.
When I first got my hands on it, it hadn't been turned on for a very long time and the power cable had been cut off. It has an external earth screw and a neutral and live wire which had been cut. I wired a mains lead, screwing the earth to the external earth screw and then connected the neutral and live wire to the mains lead. When I plugged it in everything powered up and all the lights came on. The radio function is all working fine (but on a high volume) and I have managed to tune it in to a couple of radio stations on MW. As for the record player, I turn the knob from the radio settings to 'G' which stands for gramophone which is the record player. When I press the start button, the platter spins around at the correct speed and the stylus automatically moves over the platter and lowers itself onto the vinyl record. But you cannot hear it at all.
After further inspection, I found that the two wires leading out of the record player inside the unit had broke off from the connector which slots in to a part in the record player. I soldered the wires back on to the connector and then powered it up. I put a record on the platter and press the start button and now, when you turn the volume up to max volume, you can very faintly and quietly hear the record playing through the speaker.
I then turn to the valves. It has 4 Marconi valves in it: N78, U709, DH77, N78.
One of the N78's was a bit dimmer and didn't get as hot as the other N78.
Because the N78 valves are the same I swapped them around, after doing that there was no sound from the record player on a high volume. So I figured that one of the N78 valves must me broken. I found out that the N78 valve that is not working was the one that was dimmer and not as hot. So, I ordered 2 replacement Marconi N78 valves which had been tested.
After I fitted the 2 new N78 valves, I plug it in and turn it on and the radio is louder on a lower volume and sounds very crackly and distorted.
I switch to the record player setting and test the record player but I cannot hear anything at all now even on max volume, I can only hear the speaker buzzing. However when I touch the needle, there is a very loud buzzing noise coming through the speaker.
In conclusion, the stylus is picking up the sound but it seems that it hasn't been amplified enough.
There is a small valve (DH77) which is the pre amp valve. I have not replaced that valve but maybe I should as it is 70 years old.
The U709 valve is larger than all the others and I think that is still working fine because when I remove it the radio doesn't do a thing.
Also, It has two removable styluses. One for 78's and another for 33's and 45's. The needle in the stylus that plays 33's and 45's broke so I am using the stylus meant for 78's on playing the records. I do not have any 78's but it does play the record fine be
Any ideas to what the problem is and what I should do next. I would love to be able to see it playing records again.
Thanks Zach.
