11-29-2015, 01:29 PM
Hi all. I am just finishing a restoration on a 37-670B. I have noticed that the power transformer seems to have been replaced. Looks like someone took the top cover off the original and put it on another core. (bottom of core reads LP 0290 C). I only read 58 ohms across the B+ secondary and about half of that from CT to each secondary lead (should be 128 ohms across the primary). The voltage chart on the schematic says I should read 380v across cap #88; I only get 334v. Consequently the grid voltages at the RF, Det/Osc, and IF amp tubes is only about half of what it should be (43 instead of 90v). Original power transformer # is 32-7640. I am wondering if anyone has the voltage specs for this transformer as I cannot seem to find them anywhere. Also if anyone could recommend a suitable replacement, that would help. Thanks,
Tim
Tim