[PeterN]

I am currently working on a 46-420 "Hippo" and need to replace the line cord with the molded-on strain relief. This presses into a hole with a "shoulder" to hold onto the chassis.

Is there a "best practice" method to secure a new line cord as this type of strain relief is no longer made?

I was thinking of grinding off the shoulder, and installing a current type of compression strain relief, but am not sure what Dremel grinding bit is appropriate for the steel chassis.

Any advice?

Regards,

PeterN

[morzh]

I do not remember what I did, but do not remember doing anything specific. I remember tehre was some grommet type thing in the hole, and that was enough to hold it.

Or you could simply tied the knot on the inside part of the cord to keep it from being yanked, and put a rubber grommet in that hole, if your original one is bad.

This is my thread on it.

https://www.philcoradio.com/phorum/showt...?tid=16902

[bridkarl]

I just did this. There’s a tool for removing these kinds of strain reliefs which can be bought. I think what I’m using is branded Heyco.

[PeterN]

Morzh,

Thanks for the reply and link to your project.

I am working on the original 1946 model (-121) and I see you have the later 1948 model (-122) with the PM speaker.

The line cord strain relief setup looks to be changed in the 1948 chassis. I read an old post from Ron Ramirez (RIP) where he said he used a Dremel to grind off the lip on these older chassis that the line cord with the molded on strain relief engages into. I will probably go that route and install a modern panel strain relief.

The old way would be to install a rubber grommet and use a U.L knot in the line cord to prevent it pulling out, but I would prefer a more secure solution.

BTW - How difficult was it to remove the tar from the electrolytic cap and re-stuff it? What did you reseal it with?

Regards,
PeterN

[PeterN]

bridkarl,

Yes I have the install tool for the modern strain reliefs, a Heyco model 29 Strain Relief Plier.

Regards,
PeterN

[MrFixr55]

IMHO, I would stick with the grommet and underwriter's knot w/ some RTV. If memory serves, the correct hole for a Heyco Clamp is shaped kinda like the mask for a "roundie" pix tube, to prevent the clamp from rotating. I can't remember if you need the Heyco pliers to insert the clamp but they are handy for removal. I actually got lucky getting the molded-on strain relief off a power cord once (Both the cord and the strain relief were rubber and, somehow, the rubber was in good shape.) I can't remember if it slid off or if I cut the wire and then drilled out the rubber, but I slid brown 18 ga wire into it and cemented it with rubber cement. It looked like the original. Think it was on an early post-war Philco AA5. I have a 48-206 that was totally unmolested, complete with back, rubber power cord and plug in perfect condition and UL sticker. Even the grille was in good shape (Styrene vs Tenite?) I bought it because a friend was restoring the cabinet for a 42PT94 that was his dad's. I had restored the chassis (rubber all over, of course). The tenite grille was a disaster, but he took the white grille from mine and used it to mold a new brown grille (complete with streaks) for his.

The 48-206 was in such good shape that I should have stuffed the caps, but just replaced them instead. I have not tried to salvage the wax exterior of paper caps. I have done the mid-late 30s vintage RCA caps which are like firecrackers, that were in my RCA 5BT and 6BT Farm Sets

[morzh]

Peter,

I'll be honest, I simply do not remember. But with the similar caps I usually see if they are:

1. Paper cartridge without aluminum shell. These often have a very hard substance (would not call it tar) on top. I chiesel out the top part until I get to the innard, then heat it up with a Milwaukee gun and use corkscrew to gut it. Sealing is brown hot glue.
PS> sometimes tthe paper is thin, and not really guttable. This doe snot happen often. I remember making a label for a Zenith Transoceanic cap and wrapping it around a improvised paper cartridge made out of a piece of some thin dense paper.
2. Aluminum cartridge inside. These are better. The top is typically black tar, and I simply pit the corkscrew in and try to heat it up and pull all out at once. Then clean, restuff and reseal with the same brown hot glue.

[PeterN]

MrFixr55,

Thanks for the reply. Yes, one needs a "dual D" shaped hole for the modern strain reliefs. On another Philco, I was successful in drilling out the existing molded strain relief, but on this radio, it is too dry and crumbly.

morzh,

Thanks for your procedure. I didn't know that hot melt glue was available in brown. I don't plan on re-stuffing the caps on this radio because it is only in average used condition. It is being done for a friend who has had it in the family since it was new, but was not stored well after it was no longer used daily (no back and pretty grimy).

[radiorich]

Hello Peter,
here is the link to one sold by radio Daze

https://www.radiodaze.com/power-cord-strain-reliefs/
Sincerely Richard

[morzh]

https://www.amazon.com/s?k=hot+glue+brow..._sb_noss_1


search by "hot glue brown".

Just make sure you get the right diameter for your glue gun.

[PeterN]

Thanks for all the responses and advice.

I decided not to grind down the "lip" on the line cord hole for a "Heyco" style strain relief. I was concerned with all the metal filings getting into places hard to remove. Even if masking off everything in the underside of the chassis.

What I did was to design and 3D print a replica of the original Philco molded on strain relief, in ABS plastic. This will get glued on to the new line cord with either thick Super Glue or epoxy (it is already a snug fit). The strain relief will get hot glued into the chassis hole, with a "ty-wrap" behind the chassis for insurance against pull out. This way the line cord could be removed in the future.

Attached is a picture of the new strain relief.

   

[bridkarl]

You could also use an Underwriter’s Knot instead of a Ty wrap . That will hold the line in place and it can be removed if the need arises.

[radiorich]

Hello Peter,
Nice Design !
Sincerely Richard

[tym]

Nicely done!