My wife and I are attempting to restore a Philco Radiobar model 528. The chassis is a 650-121. THe fellow that brought us the radio told me it was his mothers. Not sure I buy that as the radio is in pretty sad shape and the speaker he brought was out of an older Philco model 87 or 89 that pedestal mounts. So, my question to the Phorum is: What is the correct speaker for this radio. I saw a thread from 2010 that asked a similar question with pictures of the set showing the speaker. Riders says the correct speaker, depending on chassis, is either a K-17 or a H-13. Can't find data on either of those. Any help would be appreciated as I'm into the first phenolic block starting the recap.
Hi Mike,
So what size spkr would mount inside the cabinet? The K spkr is an 8" and the H is 10 1/2". The 87 and 89 are two very different from each other (87 is from 1929 and the 89 is from 1934).
The 37-650 has whats called a push/pull 6F6 output stage which requires a transformer will match about 14,000 ohm to the 2 ohm voice coil. This is a common configuration on Philco sets. The other consideration is the field coil. It's 450 ohms but the resistance isn't very critical as it doesn't determine the bias voltage. What is important is coil's current rating. Spkr info can be found here: Look for speaker zip file. http://philcoradio.com/phorum/showthread.php?tid=215
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 03-26-2018, 09:49 AM by Radioroslyn.)
Hi Terry. The chassis is a 650 not 37-650. The Radiobar is either a '36 or '37 radio but not sure. Ron's data would seem to point to a '36 but the radiobar guys were NOT consistent. The pictures on Ron's site show the model to be a 528 in wood not white. Output is a pair of 42s driven by another 42. It looks like an 8" speaker judging by the marks on the speaker board. The speaker shown in the 2010 thread also shows a speaker that is larger than 7". Riders says K-17 or H-13. I "think" the K-17 is right. Just looking for 1) confirmation and 2) a speaker. I have the speaker spreadsheet. Got it from John Goller last week along with a pile of other data on Philcos.
Thanks for the reply. Mike.
PS, the pedestal speaker the owner had "looked" like speakers from the 87 radios that had them mounted on a horizontal board behind the speaker grille. I have a model 87 low boy and an 87 hi boy with a similar speaker.
Philco's 8" spkrs are a bit smaller than 8" like 7 3/4. They are not a standard size, an 8" replacement spkr won't match up with mounting holes. The 650 is a horse of a different color as it's much easier to service and it does use Philco's Super Class A output stage w/ triode connected 42's and a 42 driver. This offers a very low distortion output. The output impedance for this set up is some what lower than the conventional pentode connected 42's or 6F6's. It's about 5.9K total.
Tech tip. You may want to check the interstage transformer (42 to the 42's) as it is a common issue for one side or the other to be open.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Thanks Terry. I'll be sure to check that xfmr. Same issue with the 55, 60 and 70 series Atwater Kent radios...inter-stage xfmr between the 45 outputs is often bad.
Thanks Ron. I had looked at your info on the site and concluded the radio we are working on has a 1936 chassis in it. THe cabinet is a 528 as shown on your radiobar flyer. Rider's volume 6 manual and the Philco general data on updates makes this 650 a series 121. I'm really trying to find out what speaker goes in the cabinet...K-17 8" or H-13 10". I appreciate your help.
Update: I found the speakerboard where my wife had it stored. The screw holes on the board measure 8" apart so I will be needing a K-17 speaker or equivalent.
Ok so here is the other side.
I have a 650 chassis with the speaker but the speaker is not a K-17.
I know Lee pulled it out the the 650 tabletop so what is going on?
It is a 10" speaker.
Hmmm,
Here is someothing I found. Supposedly it is an early 16B speaker but modified to work in the 650.
The numbers match but the H-13 may have faded away.
The 650B tombstone left the factory with a K-17 speaker.
650 console models left the factory with an H-13 speaker.
If a 650B tombstone had an H-13, not only would it not fit, someone would have had to rig some way to make it work. Plus those speaker screws (spaced for the K-17 speaker) would be poking the cone of the H-13 unless a thick backing board were cut and installed by someone. It was not done at the factory.
Who is Lee?
I looked at your link...the discussion there concerns model 16B, not model 650. (I know, the same speakers were used in the 650.)
I can only add this quote from Rev. Mason (RIP):
"You don't have to believe me. You have every right to be wrong if you want to be."
Im not disagreeing. I was just looking at the number on the speaker I have. It matches the one in that post I linked.
This one has a little addition to the side where it was adapted I guess. Ugh... I cant use this now, lol...
Oh, sorry, do you mean the number on the side of the actual field coil? That isn't surprising to me, both speakers having an 1140 ohm field coil and the same size "pot", it makes sense that Philco would have used the same field coil and "pot" for both K-17 and H-13 speakers.
