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

Thread Closed

EICO 320 Signal Generator
#12

I've restored about a dozen or so Heathkit/Eico/Knight signal generators.  Got at least eight more awaiting their turn.  Each one is a lot of fun to do and the transformation always satisfying.  

Now I do the dropping resistor just a little differently.  I add it in the secondary, just between the transformer and the 1N4007 diode which replaced the selenium rectifier.  It limits the inrush current to the first filter capacitor, (usually a 20/22 ufd).  A half watt resistor is all thats needed.  I determine the value of the added resistor by clipping a 10K pot where the new resistor will be.  Then adjust the pot to dial in the proper voltage for the B+.  It runs between 200 ohms and 1K.  All depends on how much voltage drop was across the old selenium diode and what the present voltage you've got coming out of the wall.  

I'm wondering if your approach is better or worse than mine?  Does the resistor run warm?  Mine doesn't.  I'll have to post a photo of a similar signal generator that's in the restoration queue, so you can see how my approach looks.  I'd bet you could make valid arguments for doing it either way.  Something to ponder.  

Mitch


Messages In This Thread
EICO 320 Signal Generator - by Crist Rigotti - 08-25-2015, 11:57 PM
RE: EICO 320 Signal Generator - by codefox1 - 08-26-2015, 07:36 AM
RE: EICO 320 Signal Generator - by Radioroslyn - 08-28-2015, 08:02 PM
RE: EICO 320 Signal Generator - by Crist Rigotti - 08-28-2015, 10:21 PM
RE: EICO 320 Signal Generator - by Mitch - 07-27-2016, 02:11 AM
RE: EICO 320 Signal Generator - by PhilcoMike - 07-27-2016, 04:04 PM
RE: EICO 320 Signal Generator - by Joe Rossi - 07-27-2016, 08:53 PM
RE: EICO 320 Signal Generator - by TV MAN - 07-28-2016, 08:19 AM
RE: EICO 320 Signal Generator - by Crist Rigotti - 07-28-2016, 10:44 AM
RE: EICO 320 Signal Generator - by gregb - 07-28-2016, 06:03 PM
RE: EICO 320 Signal Generator - by PhilcoMike - 07-29-2016, 04:08 PM
RE: EICO 320 Signal Generator - by Crist Rigotti - 07-31-2016, 11:08 PM
RE: EICO 320 Signal Generator - by Mitch - 07-30-2016, 01:38 AM
RE: EICO 320 Signal Generator - by PhilcoMike - 08-01-2016, 03:08 PM
RE: EICO 320 Signal Generator - by Crist Rigotti - 08-02-2016, 11:09 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
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
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM

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

>