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

4x6 Speaker Question for 42-345
#15

An interesting thought, Terry. That would explain why there is only 1 terminal.

Philco is the only company that I have seen the "extra speaker connection" without a suitable tap on the output transformer, so your theory makes sense. However, I wonder if there was a Cost Analyst weighing ease of testing against the cost of the screw and 5.2" of #22 wire? (Length and gauge a tongue in cheek estimate.)

CDoyl, regarding replacing your original speaker with a modern PM speaker, it comes down to originality and original performance vs relative cost and possible improvement in performance. Newer speakers with better cone materials, stronger magnets and better "cone excursion" far outperform the original speakers. This may be a plus if you are going to pipe external audio through an aux jack (mp3, computer feed, etc.) The hum issue caused by replacing the field coil with a resistor (and elimination of the important hum bucking coil) can be mitigated by increasing the value of the filter capacitors, but there is a limit to this. I used to think that one can just throw in about 100 - 200 mF worth of caps in the circuit (hey, they do it on modern solid state stuff, right?) until i got the plates of the rectifier glowing red. (Oh gee, that's right, the bigger the cap, the higher the charge current drawn.) The specs of the rectifier tube in this radio do not allow for more than 30 uF as the "input cap" unless "impedence" is added in the circuit feeding the rectifier. One can likely go with 30 / 30 mF and get a low hum. One guide is to find a schematic for a similar "Post war" version of the set, as the Alnico magnets developed for the military largely replaced field coils in post war radios.

By far, the easiest route to take is to have the original speaker re-coned. I have never had this done, (I am a hacker by heart) but trust the opinion of the Pholks on the Phorum recommending that you do so.

In the meantime, you can "check out" the radio by mountig the original speaker where it belongs, and since the voice coil is now missing, connect the new speaker either across the voice coil connections of the old speaker or as I described in the previous post.

"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
4x6 Speaker Question for 42-345 - by cdoyal - 02-07-2022, 07:39 PM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-07-2022, 09:36 PM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-07-2022, 10:08 PM
RE: 4x6 Speaker Question for 42-345 - by cdoyal - 02-08-2022, 10:19 AM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-09-2022, 07:09 AM
RE: 4x6 Speaker Question for 42-345 - by cdoyal - 02-09-2022, 11:58 AM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-09-2022, 02:29 PM
RE: 4x6 Speaker Question for 42-345 - by cdoyal - 02-12-2022, 09:51 PM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-13-2022, 03:28 PM
RE: 4x6 Speaker Question for 42-345 - by cdoyal - 02-20-2022, 01:58 PM
RE: 4x6 Speaker Question for 42-345 - by MrFixr55 - 02-20-2022, 10:04 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Need to purchase some accessories for restoration of my Old Philco Radio
Here is a list of resources found in our online library that you might find useful. Mike's Gobs of Knobs email addres...klondike98 — 01:46 PM
First Radio restoration
Hi Tubeman, Welcome to the Philco Phorum.  Phamily Phriendly Pfun with Phine Pholks Phull of Philco Phacts. (See a p...MrFixr55 — 12:33 PM
First Radio restoration
You could post in the WANTED ADs section here on the Phorum and see if anyone has an RF generator that they want to sell...klondike98 — 11:55 AM
Zenith H725
Good ideas, thank you Arrange and Rich. I have the adhesive aluminum foil already and can try that immediately. More ...EdHolland — 10:18 AM
Graphics for majestic 1050 dial glass.
Murf; I found this thread on the ARF, the first photo has a pretty good view of the dial glass. Regards ArranArran — 01:12 AM
Zenith H725
hello Ed, how about that speacial tape used for ducting it's like foil or how about thin piece of aluminum roof flash...radiorich — 12:19 AM
Zenith H725
Ed; One material that I have seen, but never tried for this was material for making exhaust gaskets, it's similar to ...Arran — 11:42 PM
Zenith H725
I just remembered, I have some hi temp silicone rubber material which could do the trick. Or a piece of FR4 laminate. Th...EdHolland — 08:39 PM
Zenith H725
The PSU filter cap arrived today (thank you USPS!) so I will work on that later. Meanwhile, I have the dial, speaker...EdHolland — 06:42 PM
Philco 610B oscillator wiring
Thanks Terry. After checking my notes I think I recorded about -10v at the 6A7 G4/control grid. The screen grid (G3 &...Tubester — 05:59 PM

[-]
Who's Online
There are currently 2607 online users. [Complete List]
» 2 Member(s) | 2605 Guest(s)
AvatarAvatar

>