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

Retrofitting speaker for Philco 84
#6

Hi CtKid,

It is rather easy to replace this speaker with a modern one. Use a 1100 Ohm 10 W resistor (20 W would be better. a 1000 Ohm or 1200 Ohm resistor will be OK also. Please note that this resistor will get real hot, so place appropriately. I would not worry too much about "impedance matching" if using an 8 Ohm resistor. If the output transformer is bad, any transformer with a 7 KOhm to 8 KOhm primary and 8 Ohm Secondary will be good.

This radio is a surprisingly good performer considering the novel 4 tube "Superhet" circuit with no IF, an "Autodyne" 1st Detector (Oscillator Mixer) circuit and a "regenerative" 2nd Detector.

If the set does not work after replacing the speaker, "ohm" the Oscilloator coil. It is common that the "tickler" (the coil in the cathode circuit) is open.

This set is not as historically significant as the Model 20, 71, etc., but is a historically important set IMHO.
This set was originally produced, in the throes of the Great Depression, as a "Loss Leader" to get people into the showroom so the salesman could "upsell" the Customer to a more expensive, higher performance set. This failed, as people bought these sets big time and over 100,000 were produced, and the set was made in various forms and upgraded models until 1937 (The 37-84 was the same circuit but used Octal tubes). The original price was $19.95, and dropped to $14.95. This forced RCA to drop the price of their "loss leader" R28 set. Many companies and dealers were angered by Philco producing this set.

"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
Retrofitting speaker for Philco 84 - by Ctkid - 09-25-2022, 06:39 PM
RE: Retrofitting speaker for Philco 84 - by Ctkid - 09-26-2022, 09:57 PM
RE: Retrofitting speaker for Philco 84 - by MrFixr55 - 09-27-2022, 08:36 AM
462ron - by 462ron - 09-29-2022, 08:29 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Zenith H725
David - I think I understand but what units are you discussing (Low of 1.7, high of 3.9)? Budget constraints for Ham ...EdHolland — 01:43 PM
My Philco 37-116 Restore
You're doing great. I wish I could be more involved, but my mind is right now preoccupied with the reason I am here in ...morzh — 12:21 PM
My Philco 37-116 Restore
Hope you guys are still with me. I have moved on to the alignment. I completed the IF alignment which was pretty muc...dconant — 10:47 AM
My Philco 37-116 Restore
Hello MrFixr55, Thank you for taking the time to explain. I measured 50 volts where you say. Today the 370 volts at ...dconant — 12:51 PM
462ron
Oh that sucks. It’s something easily overlooked. Hopefully it’s nothing more than a resistor! Ron462ron — 08:08 AM
Philco 46-480 Electronic Restoration
Just confirmed that you are correct. It’s the function generator. I connected the signal output probe to one of the inpu...jrblasde — 07:52 AM
Philco 46-480 Electronic Restoration
Ouch, you may be right. Yes, it is solid state. It’s the signal output of my oscilloscope. May be time to crack that ...jrblasde — 07:27 AM
462ron
If you didn’t put a DC blocking cap between the signal generator probe and the plate of the 1st IF it’s possible you ble...462ron — 07:07 AM
My Philco 37-116 Restore
Hi DConnant, The reason why C127 is isolated from ground is because sets of this vintage did not have the center tap...MrFixr55 — 01:07 AM
Philco 46-480 Electronic Restoration
The shield is on the 6H6. It was, in fact, a missing jumper to connect the main chassis ground to the RF chassis grou...jrblasde — 10:58 PM

[-]
Who's Online
There are currently 1057 online users. [Complete List]
» 3 Member(s) | 1054 Guest(s)
AvatarAvatarAvatar

>