Philco 70A

Thread Rating:

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

Linear Mode

Philco 70A

Arran
Phorum Expert

Posts: 4,703
Threads: 51
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 »

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: 2 Guest(s)

Recent Posts
Model 28L
For 28 you will probably need to buy a Hammond 125CSE. Or any of the series of the power you need, with SE suffix. Then ...morzh — 02:09 PM
37-60 revision 6
I am restoring a Philco 37-60 and it shows run 6 they removed the ground from G3 of the 6K7G and put the G3 to -2.5v for...bobbyd1200 — 01:01 PM
Shadow Meter Bulb
Mike is correct on the bulb connection, two separate circuits. I found that by rotating the bulb and sliding it forward ...RodB — 12:19 PM
Hickok AC51 tube tester
Cleaned ann contacts, switches and sockets, works great now.martinj — 11:32 AM
Model 28L
Hello, I'm restoring a Philco 28L and the output transformer is open. Part number of the transformer is 32-7020. Can...HORSTE — 10:32 AM
Philco 42-1008 conversion kit
I read about a kit to convert the variable speed changer in the Philco 42-1008 into a single speed unit. That would rem...alangard — 09:30 PM
HiFi (Chifi) tube amp build - but my own design.
Tim Well...a chassis is metal. Magnetic or not, it does not matter. A transformer has some hum to it. It is natural. Th...morzh — 08:40 PM
Hickok AC51 tube tester
I thought the 83 tube was bad because it looked white but it tests strong. Blue gassy though. I checked the fuse, it was...martinj — 08:37 PM
Shadow Meter Bulb
Ross I am not sure what current limiting effect the incandescent provides. They are two different parts of the sch...morzh — 08:31 PM
12' Philco
Bob Thanks for that photo. I have been looking for it, and I cannot find anythinmg on the web. I forgot it was here...morzh — 08:29 PM

Who's Online

There are currently 5562 online users. [Complete List]
» 2 Member(s) | 5560 Guest(s)

Login
Username:
Password:	Lost Password?
	Remember me