Re: HMV 1804 Television.
Hi Andy,
It's all a bit of a dilemma, do I return the set back to it's original EMI design or tidy up the work that some unknown engineer had done more than sixty years ago? Why anyone should have gone to all the trouble of redesigning the signal circuits in such a manner is a mystery. As mentioned earlier, some sort of external frequency shifter device to receive the Birmingham TX would have been an easier solution. In 1982 I acquired an Ekco TS46 in which someone had fitted such a device in order this TRF receiver could receive a local transmitter in the West Country. Just one valve was employed, a 6A8GT pentagrid frequency changer valve.
There's no doubt the conversion work has been done in a competent manner, whoever done all this work knew what he doing.
Meanwhile work is progressing on the set. The resistance measured between the HT rail to chassis is now over 35Kohms. It was just a few Kohms.
I'm prepared for the EHT transformer to fail. The same component in my Marconi VT50 has done so already. The VT50 and 1804 are electrically identical, just differently styled cabinets.
Picture of the VT50.
DFWB.
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