Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 41-300 output transformer question.
#7

The rep, as you can see, has said exactly what we had said before. You need 10K impedance.

As for the turns ratio, it is the simplest of all:

1. connect the primary of your transformer to a Variac and inject, say, 20V in it (measured with the primary connected). This is your Vin.
2. While continuing injecting the voltage in the primary, connect the meter to the secondary and measure the voltage. This is your Vout.
3. Your Vin/Vout ratio is your turns ratio W.

Now,

4. Your Turns ratio squared times your output impedance (say you have 8 Ohm) is your primary impedance. Say you have W=35 (you measure Vout = 0.57V at Vin =20V). Then your input impedance is 8*35*35 = 9800 Ohm which is what you need.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.


Messages In This Thread



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Jackson 715 not working
Now that you posted the schematic, I don't know why that Sprague electrolytic cap is across the meter, as it is not indi...MrFixr55 — 05:51 PM
HiFi (Chifi) tube amp build - but my own design.
What may be lacking in the PP Tube amps may be the 2nd harmonics, which some, especially RCA back in the day called &quo...MrFixr55 — 05:32 PM
Jackson 715 not working
Usually in an emission tester, the tube under test is measured as if it were a diode. So, some testers connect all the g...RodB — 04:17 PM
Restoring Philco 37-604C
Yep. F5 is green, D5 is Red. Red is Bad. Green is Clean.morzh — 01:30 PM
Jackson 715 not working
I did start to do that but I stalled out because I could not figure out how the grid and plate get voltage. In this diag...daveone23 — 11:52 AM
Restoring Philco 37-604C
(Insert Homer Simpson "DOPF" Here.) When all fails, look at the can. Took the Ron Ramirez advice, red Caig D...MrFixr55 — 09:23 AM
Philco 91 Speaker Replacement
From your text I am not sure if you intend to use the existing speaker with a resistor instead of the field coil. It wo...morzh — 08:44 AM
Philco 91 Speaker Replacement
My field coil is bad. I am still hoping to find an original, but if I can't I will go with a fitting Philco speaker, 125...dconant — 08:34 AM
Philco 91 Speaker Replacement
As Rod said, it is OK to use a fitting speaker, and then look for an original one. If you buy a Hammond 125 output tr...morzh — 08:15 AM
Philco 91 Speaker Replacement
Yes, I often have to substitute, then keep an eye out for an original. In the meantime, the radio is working and being e...RodB — 08:02 AM

[-]
Who's Online
There are currently no members online.

>