28-10-2023, 04:04 PM
The A24 chassis is working and giving a good account of itself. Excellent sensitivity, especially at the HF end of the medium waveband. Not so good on the long waveband.
Selectivity is excellent as one would expect with a receiver having a low IF, 117Kc/s.
Thanks to the thorough HT smoothing the hum level from the loudspeaker is very low.
The original mains transformer had terminals for mains voltage selection and the loudspeaker field coil. The replacement Elstone transformer had no such items. A new terminal panel has been made, the brackets glued into position using Evostik "Serious Glue" it gives a very strong bond between the brackets and the transformer frame.
The HT rectifier is a Marconi U12 It would seem Murphy preferred to employ M.O. rectifiers instead of Mazda, at least in the early models.
The chassis is now installed in the A24 cabinet.
Geordie McBoyne.
Selectivity is excellent as one would expect with a receiver having a low IF, 117Kc/s.
Thanks to the thorough HT smoothing the hum level from the loudspeaker is very low.
The original mains transformer had terminals for mains voltage selection and the loudspeaker field coil. The replacement Elstone transformer had no such items. A new terminal panel has been made, the brackets glued into position using Evostik "Serious Glue" it gives a very strong bond between the brackets and the transformer frame.
The HT rectifier is a Marconi U12 It would seem Murphy preferred to employ M.O. rectifiers instead of Mazda, at least in the early models.
The chassis is now installed in the A24 cabinet.
Geordie McBoyne.
