Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Zenith H725
#2

Ed, I have one of these and the performance is rather surprising considering the 1.0 - 1.5W output stage.  Having an 8" speaker and a solid state rectifier instead of a 35W4 certainly helps the performance of this unit.

The schematic is available on Nostalgia Air.  Most of the caps in the set may be ceramic disks.  The electrolytic on my et is still good.

Do be careful of these issues:
  • The set may have a 35B5 or a 35C5.  They are not interchangeable; the basing diagrams are different.
  • This is a true "Hot Chassis" set with the B- and low side of the filament string, along with the chassis connects to the power switch.  This means that if the chassis is at neutral potential with the power switch closed, it will be hot with the switch open. and visa versa if the plug is reversed.  The set does have an interlock.  I would recommend installing a polarized plug and move the switch to the Hi side of the filament string and input to the rectifier, to ensure that the chassis is always at neutral potential.
  • The rectifier is selenium.  these do go bad and stink then they do.

Hope this helps.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55


Messages In This Thread
Zenith H725 - by EdHolland - 03-17-2025, 09:45 PM
RE: Zenith H725 - by MrFixr55 - 03-17-2025, 10:24 PM
RE: Zenith H725 - by EdHolland - 03-18-2025, 11:52 AM
RE: Zenith H725 - by David - 03-18-2025, 01:48 PM
RE: Zenith H725 - by EdHolland - 03-18-2025, 06:09 PM
RE: Zenith H725 - by Arran - 03-18-2025, 10:08 PM
RE: Zenith H725 - by RodB - 03-19-2025, 10:04 AM
RE: Zenith H725 - by EdHolland - 03-19-2025, 10:46 AM
RE: Zenith H725 - by morzh - 03-19-2025, 12:38 PM
RE: Zenith H725 - by RodB - 03-19-2025, 12:55 PM
RE: Zenith H725 - by morzh - 03-19-2025, 01:25 PM
RE: Zenith H725 - by David - 03-19-2025, 03:49 PM
RE: Zenith H725 - by Arran - 03-19-2025, 04:45 PM
RE: Zenith H725 - by Paul Philco322 - 03-19-2025, 08:13 PM
RE: Zenith H725 - by EdHolland - 03-20-2025, 12:34 PM
RE: Zenith H725 - by MrFixr55 - 03-20-2025, 12:59 PM
RE: Zenith H725 - by EdHolland - 03-20-2025, 08:40 PM
RE: Zenith H725 - by MrFixr55 - 03-21-2025, 08:59 AM
RE: Zenith H725 - by radiorich - 03-21-2025, 09:29 AM
RE: Zenith H725 - by EdHolland - 03-21-2025, 09:41 PM
RE: Zenith H725 - by MrFixr55 - 03-21-2025, 09:53 PM
RE: Zenith H725 - by EdHolland - 03-22-2025, 03:17 PM
RE: Zenith H725 - by EdHolland - 03-22-2025, 06:09 PM
RE: Zenith H725 - by RodB - 03-22-2025, 06:52 PM
RE: Zenith H725 - by Arran - 03-22-2025, 07:05 PM
RE: Zenith H725 - by MrFixr55 - 03-22-2025, 08:34 PM
RE: Zenith H725 - by EdHolland - 03-22-2025, 08:40 PM
RE: Zenith H725 - by radiorich - 03-22-2025, 10:22 PM
RE: Zenith H725 - by radiorich - 03-22-2025, 10:35 PM
RE: Zenith H725 - by MrFixr55 - 03-22-2025, 10:39 PM
RE: Zenith H725 - by radiorich - 03-23-2025, 12:17 AM
462ron - by 462ron - 03-23-2025, 08:54 AM
RE: Zenith H725 - by Paul Philco322 - 03-23-2025, 09:18 AM
RE: Zenith H725 - by EdHolland - 03-23-2025, 10:37 AM
RE: Zenith H725 - by radiorich - 03-23-2025, 11:31 AM
462ron - by 462ron - 03-24-2025, 08:22 AM
RE: Zenith H725 - by radiorich - 03-24-2025, 08:34 AM
RE: Zenith H725 - by EdHolland - 03-24-2025, 02:44 PM
RE: Zenith H725 - by EdHolland - 03-24-2025, 06:56 PM
RE: Zenith H725 - by radiorich - 03-24-2025, 10:33 PM
RE: Zenith H725 - by EdHolland - 03-24-2025, 10:46 PM
RE: Zenith H725 - by Arran - 03-24-2025, 11:42 PM
RE: Zenith H725 - by EdHolland - 03-25-2025, 11:49 AM
RE: Zenith H725 - by Arran - 03-25-2025, 06:40 PM
RE: Zenith H725 - by EdHolland - 03-25-2025, 06:42 PM
RE: Zenith H725 - by EdHolland - 03-25-2025, 09:13 PM
RE: Zenith H725 - by radiorich - 03-26-2025, 01:02 AM
RE: Zenith H725 - by EdHolland - 03-27-2025, 10:57 AM
RE: Zenith H725 - by EdHolland - 03-27-2025, 04:25 PM
RE: Zenith H725 - by EdHolland - 03-27-2025, 11:08 PM
RE: Zenith H725 - by EdHolland - 03-28-2025, 03:45 PM
RE: Zenith H725 - by EdHolland - 03-28-2025, 09:53 PM
RE: Zenith H725 - by radiorich - 03-29-2025, 01:27 AM
RE: Zenith H725 - by MrFixr55 - 03-29-2025, 02:33 PM
RE: Zenith H725 - by David - 03-29-2025, 06:28 PM
RE: Zenith H725 - by EdHolland - 03-31-2025, 12:16 PM
RE: Zenith H725 - by rfeenstra - 03-31-2025, 02:37 PM
RE: Zenith H725 - by RodB - 03-31-2025, 02:41 PM
RE: Zenith H725 - by EdHolland - 03-31-2025, 03:03 PM
RE: Zenith H725 - by EdHolland - 04-02-2025, 06:42 PM
RE: Zenith H725 - by EdHolland - 04-02-2025, 08:39 PM
RE: Zenith H725 - by Arran - 04-02-2025, 11:42 PM
RE: Zenith H725 - by radiorich - 04-03-2025, 12:19 AM
RE: Zenith H725 - by EdHolland - 04-03-2025, 10:18 AM
RE: Zenith H725 - by EdHolland - 04-04-2025, 06:18 PM
RE: Zenith H725 - by Paul Philco322 - 04-04-2025, 08:27 PM
RE: Zenith H725 - by EdHolland - 04-04-2025, 09:08 PM
RE: Zenith H725 - by radiorich - 04-05-2025, 01:03 PM
RE: Zenith H725 - by EdHolland - 04-05-2025, 06:10 PM
RE: Zenith H725 - by EdHolland - 04-06-2025, 04:04 PM
RE: Zenith H725 - by EdHolland - 04-06-2025, 07:40 PM
RE: Zenith H725 - by Arran - 04-07-2025, 02:34 PM
RE: Zenith H725 - by EdHolland - 04-07-2025, 05:32 PM
RE: Zenith H725 - by EdHolland - 04-08-2025, 05:51 PM
RE: Zenith H725 - by Arran - 04-08-2025, 06:34 PM
RE: Zenith H725 - by EdHolland - 04-08-2025, 08:23 PM
RE: Zenith H725 - by David - 04-08-2025, 08:52 PM
RE: Zenith H725 - by EdHolland - 04-10-2025, 01:43 PM
RE: Zenith H725 - by David - 04-10-2025, 04:06 PM
RE: Zenith H725 - by EdHolland - 04-10-2025, 06:06 PM
RE: Zenith H725 - by EdHolland - 04-20-2025, 05:09 PM
RE: Zenith H725 - by Paul Philco322 - 04-20-2025, 07:13 PM
RE: Zenith H725 - by David - 04-20-2025, 08:47 PM
RE: Zenith H725 - by radiorich - 04-21-2025, 09:43 AM
RE: Zenith H725 - by EdHolland - 04-24-2025, 08:04 AM



Users browsing this thread: 3 Guest(s)
[-]
Recent Posts
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
That looks a lot like an aircraft connector of some kind, even if it's a U.S.N power supply. I have a book somewhere abo...Arran — 02:56 AM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
hello david, I have a similar generator in my collection that features a cast iron, single-cylinder Briggs & Stratt...radiorich — 01:00 AM
under chassis parts locator diagram for 1938 Zenith 9s262
Has anyone gone to the trouble of creating an under chassis parts locator image?  Yes, I can identify components by foll...bobloney — 08:57 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Try looking at this site the book mark is for a old generator that I was given. David    https://radionerds.com/index.ph...David — 08:36 PM
Plug Voltages Needed For A 1943 CRV-20130 Power Supply
Hello Everyone, I am looking for voltage identification for all the pin positions on the socket of a CRV-20130 power su...Tonym4704 — 08:16 PM
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM

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

>