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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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26th Sep 2022, 5:22 pm | #1 |
Pentode
Join Date: Oct 2013
Location: Winnipeg, Canada
Posts: 116
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TF 957/1 H.F. Absorption Wattmeter
I have just recently purchased one of these Wattmeters and am in the process of getting familiar with it. This particular model was the North American export version of the original TF 957, also built by Marconi Instruments Ltd, and differs from the original only in that both test terminals are rated at 52 Ohms and use BNC fittings. The other significant change for the North American market was to convert the fasteners for the cover from the original four captive screws to a simple pair of latch clips.
One of the latches on my meter is missing its Spring Assembly. It turns out these latches are identical to those used on the case of the Wireless Set No. 31 late in World War 2. Does anyone know of a source of supply for these latch parts today. Or have one of these springs available? I was hoping for a manufacturers name on the two latch handles on the meter, but all that is still readable from the ink stamps is: MADE IN ENGLAND …bits of a number… It makes sense Marconi Instruments would not have gone to the trouble of designing special latches for this item if something suitable was already available in the 1950’s. They must have done a good job designing this meter. It was last calibrated in April, 1994 and both terminals are still reading 52 Ohms. David VE4DTD |