26-04-2018, 07:29 AM
Hi, new to this group, and also valve gear.
I have acquired a VM77D from a relative. First powered up via light bulb to limit current, all seems OK, and now powered up directly, again all seems OK, main caps seem to hold voltage well. Question is on the heater voltage. This is quite high at 6.7v - should I be worried and look at reducing this somehow? I note the input voltage range is quite wide 200-250v, and my mains supply is generally above 240V so I guess it should be OK. These instruments are unlikely to be on for very long periods, so perhaps not a problem.
Not tested calibration or anything else yet, but it does read values if I connect a lead to the input as an antenna, so looks promising.
73
Dave M0WID
I have acquired a VM77D from a relative. First powered up via light bulb to limit current, all seems OK, and now powered up directly, again all seems OK, main caps seem to hold voltage well. Question is on the heater voltage. This is quite high at 6.7v - should I be worried and look at reducing this somehow? I note the input voltage range is quite wide 200-250v, and my mains supply is generally above 240V so I guess it should be OK. These instruments are unlikely to be on for very long periods, so perhaps not a problem.
Not tested calibration or anything else yet, but it does read values if I connect a lead to the input as an antenna, so looks promising.
73
Dave M0WID
