Philco 70A

Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed

Thread Rating:

0 Vote(s) - 0 Average
1
2
3
4
5

Linear Mode

Philco 70A

Arran
Phorum Expert

Posts: 4,816
Threads: 54
Joined: Sep 2008
City: Sandwick, BC, CA

#23

06-19-2015, 10:36 PM

Actually there are many advantages to owning a set equipped with a 25 cycle compatible power supply, as most have noticed the power transformer is larger, because the core is larger in order to avoid saturation at the lower line frequency. However in addition to the power transformer they would add electrolytic caps of a larger value and often add extra filter chokes or increase the size of the field coil or of the filter chokes to eliminate the 25 cycle ripple. So if you run a 25 cycle set on 60 cycles the transformer will run cooler, can tolerate more abuse, and there will be next to no hum.
Regards
Arran

Find

« Next Oldest | Next Newest »

Thread Closed

Messages In This Thread

Philco 70A - by Crist Rigotti - 06-17-2015, 11:24 PM

RE: Philco 70A - by Phlogiston - 06-18-2015, 12:25 AM

RE: Philco 70A - by morzh - 06-18-2015, 09:41 AM

RE: Philco 70A - by Crist Rigotti - 06-18-2015, 09:47 AM

RE: Philco 70A - by Phlogiston - 06-18-2015, 10:38 AM

RE: Philco 70A - by Crist Rigotti - 06-18-2015, 10:41 AM

RE: Philco 70A - by Steve Davis - 06-18-2015, 12:25 PM

RE: Philco 70A - by Steve Davis - 06-18-2015, 12:31 PM

RE: Philco 70A - by GarySP - 06-18-2015, 12:52 PM

RE: Philco 70A - by TA Forbes - 06-18-2015, 01:03 PM

RE: Philco 70A - by Crist Rigotti - 06-18-2015, 02:34 PM

RE: Philco 70A - by Ron Ramirez - 06-18-2015, 05:53 PM

RE: Philco 70A - by Crist Rigotti - 06-18-2015, 08:25 PM

RE: Philco 70A - by Ron Ramirez - 06-18-2015, 08:51 PM

RE: Philco 70A - by morzh - 06-18-2015, 08:57 PM

RE: Philco 70A - by Crist Rigotti - 06-19-2015, 02:03 PM

RE: Philco 70A - by plymouthrod - 06-19-2015, 02:25 PM

RE: Philco 70A - by Crist Rigotti - 06-19-2015, 04:16 PM

RE: Philco 70A - by Ron Ramirez - 06-19-2015, 05:38 PM

RE: Philco 70A - by KCMike - 06-19-2015, 07:53 PM

RE: Philco 70A - by Crist Rigotti - 06-19-2015, 09:47 PM

RE: Philco 70A - by Ron Ramirez - 06-19-2015, 10:26 PM

RE: Philco 70A - by Arran - 06-19-2015, 10:36 PM

RE: Philco 70A - by Crist Rigotti - 06-19-2015, 10:41 PM

RE: Philco 70A - by Crist Rigotti - 06-19-2015, 11:21 PM

RE: Philco 70A - by KCMike - 06-20-2015, 01:51 PM

RE: Philco 70A - by Crist Rigotti - 06-20-2015, 07:51 PM

View a Printable Version

Users browsing this thread: 7 Guest(s)

Recent Posts
An attempt to remove the Field Coil from a G speaker
Gary I in fact did, on a 38-14, I think, where I had a speaker with the dead coil. Well...it kinda worked. Kinda, be...morzh — 10:38 PM
An attempt to remove the Field Coil from a G speaker
Mike, what ever happened to that plan you had to try using a rare earth magnet to magnetize the pole? This looks like a...GarySP — 10:25 PM
RCA T62 is playing.....
Beautiful set.morzh — 09:07 PM
An attempt to remove the Field Coil from a G speaker
Well....here it is. The green stuff. Unfortunately, probably penetrates deep. I opened the top layer and saw that: ...morzh — 08:58 PM
Philco 91 Restore Code ??
:clap: :clap: :clap: :clap: Really nice workmanship!!! Top of the chassis looks great. Sorry about the long winded e...MrFixr55 — 08:09 PM
Philco 40-120C Restoration
Thank you for your reply. I will check voltages on the other tubes, look at resistor 23 and cap 25, etc. If all else fai...bluecap — 07:58 PM
RCA T62 is playing.....
Nice looking set great save. DavidDavid — 07:48 PM
Philco 89 indicator light.
Hello Jim, I have done several 89s. The trick is to move the drum in or out on it's shaft. You will need to loosen a set...dconant — 07:36 PM
An attempt to remove the Field Coil from a G speaker
MrFixr Yes, it is my plan to go with 45rpm spider if I go that far. No, the pole was not left-handed as I unscrewed ...morzh — 07:14 PM
Philco 40-120C Restoration
Change the tube. Check the tube's bias network. Are any other tubes experience the drop or just this?` Is resistor 23 OK...morzh — 07:09 PM

Who's Online

There are currently 6645 online users. [Complete List]
» 1 Member(s) | 6644 Guest(s)

Login
Username:
Password:	Lost Password?
	Remember me