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Philco 620 bakelite block
#16

Wow! Didnt mean to stir up a fuss round here at all! All my point was, is I dont find spending time rebuilding bakelight blocks one of my favorite things to do even tho I could if I wanted too. Personally, I like to leave my recapping jobs well marked and fully visable using terminal strips for future generations of restorers to be able to identify components without having to remove screws and look inside , or have to purchase a copy of "Philco condensers & more" to get a recap job done. I do admire all that keep "originality" to radio sets, ( nice Philco 90s), but I dont think anyone other than us techs really care much what the "under chassis" looks like, and it is our preference if we care to make it easier in the future for someone else to keep these sets working by easily identifying componets. I see plenty of confusion posted here on this forum by "newbies" trying to decipher those old philco part #s to make my point valid. Now if were talkin early A-K breadboards, I would say keep em all original, otherwise, I dont see the point of restuffing (mystery) caps as a good practice personally. I usually restore about 25-30 vintage radios for customers per yr. I like to be able to see what Im working on, and Im sure future generations that recap my past works will be appreciative of my taking the "mystery" out from under many of the vintage Philco chassis. Reckon? Just a thought. Peace Ya'll, ol TxRockr
#17

Texasrocker:

Point well made, here is an area I will agree with you and need your help.

1. I am replacing a cap in the radio, one that a former repairer used to do away with part 30 2079, the 8 mfd - 8 mfd condenser. The new caps I have to replace it with are blue colored 10uf caps, with a white arrow and a minus sign in the arrow. Question, does this arrow mean that the direction pointed in is the negative side of the cap? Further, the negative ends of these new caps apparently are to be tied together as a common ground or negative side, correct?

2. I am replacing the part # 30 2118 condenser 16 mfd cap with a new blue 16uf cap. Can you give me some instructions on how to bypass the old can and put this new cap in the chasse? Thanks much, have a great day in the Lord. Icon_smile


Dave
#18

Hi Dave

Answers inline...

David B Wrote:1. I am replacing a cap in the radio, one that a former repairer used to do away with part 30 2079, the 8 mfd - 8 mfd condenser. The new caps I have to replace it with are blue colored 10uf caps, with a white arrow and a minus sign in the arrow. Question, does this arrow mean that the direction pointed in is the negative side of the cap? Further, the negative ends of these new caps apparently are to be tied together as a common ground or negative side, correct?

In most modern electrolytics, the arrow with the MINUS (-) sign points to the NEGATIVE lead of the electrolytic.

In your 620, yes, the two negative leads of the two 10 uF electrolytics will be connected together, and connect to B- (NOTE that they do NOT connect direct to ground!) at the top of resistor (70), with the center tap of the high voltage secondary, which is the B- source, also connected there.

David B Wrote:2. I am replacing the part # 30 2118 condenser 16 mfd cap with a new blue 16uf cap. Can you give me some instructions on how to bypass the old can and put this new cap in the chasse?

For condenser (52), your 16 uF electrolytic, the POSITIVE lead connects to the junction of resistors (47), ( 48 ) and (49). See your schematic. The NEGATIVE lead of the 16 uF electrolytic connects to chassis ground.

49Stude63 gave you some excellent advice on rebuilding the electrolytics. If you do not feel comfortable with trying that yet, you may place the new electrolytics under the chassis at any convenient point; just be sure your work is neatly done, and that the old electrolytics are completely disconnected from the circuit!

--
Ron Ramirez
Ferdinand IN
#19

One thing to remember on the bakelite blocks once you rebuild them then there is no more mystery since if you remove the screw and turn them upside down then the caps or resistors are clear for anyone to see. If I use yellow mylars I position the values so the are clear to see once the block is unbolted from the chassis. Then the circuits match what the user would see if they are using philco repair data. I also put a copy of the schematics in with the radio under the chassis or in an envelope and note what was done so 20-40 yrs from now if someone has to repair it again everything is there will clears descriptions on what was done, I have done the hard work (rebuilding the blocks originally) and all they would need to do is de-solder the bad cap and solder in a new one. I like to keep the originality of the radio if possible, even for details like grille cloth, type of finish (lacquer) correct as possible color scheme etc. I even go to the effort to use the correct tube type G style vs GT or metal style tubes but again that is always up the the person doing the restore. For any newbie it is always nice to know and understand the various possibilities and they can decide which or what method they want to choose. In the future I look for more information to be available than it is now if the antique radio hobby continues to thrive. It may be in 20-30 yrs that this hobby may be all but dead since the once doing it now are no longer around the the younger people don't see it as a viable hobby. Those type of trends are hard to predict so making it easier for the next guy is not an overwhelming concern for me since it may be 30-50 yrs before the radio needs a repair again since the amount of listening a user does now will never come close to the amount of "on" time that the radio was exposed to when it was new or in it's prime in the 30-50's when radios were the basic entertainment.
#20

Thank you tremendous information, and insight. God bless you

Dave
#21

Texasrocker Wrote:Re-stuffing orig caps is rediculous IMO, and once you get those old orig bakelight housings out of the way, the orig screw-hole in the chassis can be used to mount a new "fully-visable" terminal strip in most cases. I have rebuilt several A-K power units in my days, and "digging tar" to get to components was never a "good-idea" in the 1st place. Now, all you "purists" can chunk rocks at me, but I will also throw many orig bakelight blocks back , or better yet, if you want to re-stuff em, I have plenty in a cardboard box under my bench if you want em. Just my .02, TR Icon_lol Icon_lol
Hello,
It's not rediculous to restuff, especially the Philco blocks. Myself and most others love to see the underside of a chassis as it should look.
You don't need to purchase any "special books" or find out about "mystery componets". There's a number on their side. About 99.99% the info you need can be found on Ron's or Chuck's sites.

What is there to figure out? One or two caps in a little bakelite block?Maybe a resistor also? It's almost a "no brainer". This is what makes re-doing a Philco unique.
No need to dig, the stuff pushes right out when warmed a bit. Install the caps, and you're done.

(Pull that complicated 426 Hemi out of the Charger and install a Slant 6, they are easier to figure out, and save space.)

As for worrying about the next generation having to figure out what's under the chassis, I think they would like to see how the Philco was originally wired, not modded and rewired by someone in the first part of the century.
The blocks don't take up valuable space.
It's your radio and do as you please, but when you trash parts of a set that were still installed, and are easy to replace, that's one less set that is not as original as it could be.


The AK power units that are filled with tar and would be hard to dig out all that stuff. I understand that totally. I know about large metal boxes on Victor R-32's that are best handled by using a terminal strip, while leaving the box intact.


This is JMHO, but if you are still changing the blocks, save them for some of the folks here, they would love to take them off your hands, seriously.
Regards,
Gary Rabbitt
and that's my
[Image: http://farm2.static.flickr.com/1088/5362...5f5d_m.jpg]




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