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48-460 antenna replacement
#1

Not sure if this post goes here or in the Cabinet thread.
My 48-460 Hippo does have the original loop that once was glued inside the chassis. It's not anymore. The loop also seems to be starting to unwind on me.

Is there somewhere replacements can be had? How/what would I use to reattach it? Can I test it to see if it's still good?

John
#2

Hello! Vintage style loop antennas are most probably still usable if the insulation on the wires are still intact between the many individual windings? Careful visual inspection will help to know if "bare wires" exist and are touching "shorting" the loop needed to acquire proper reception as originally designed. Loop antennas were originally wound by the mfgrs to "balance" the many different brands & models type sets produced to exactly-correct the antennas path into the radio receivers circuitry designed for many different particular designs. Also, make sure the "leads" from the antenna havent broken off due to flopping-around un-attached. A close visual-inspection will sometimes help!
As far as re-attaching loop antennas to orig locations, using clear-silicone ( such as clear GE silicone household adhesive avail in a hand-squeeze type tube), has worked well for me. No conductive loss at all! Any broken antenna leads ( if any) will need to be re-soldered back as necessary. As far as replacements if needed, check Antique Electronic Supply catalog. http://www.tubesandmore.com online They offer a new loop ant replacement ( much smaller in design than originals were) I have used several times before in the past. Good luck with your Philco!! Just bet your orig antenna is still usable if connected properly? Just a guess. Icon_wink
#3

I may get lucky, as the original antenna is still attached at the terminals, as well it seems to be intact otherwise except for the fact that one or two turns of the antenna wire have "broken free" from the loop. I'll just have to check it out later after I get it recapped.
#4

The loop antenna beginning to unravel is a common malady with postwar Philco table model sets. I can not recommend the use of silicones because most silicones will eat through copper unless it is designed for use with electronic equipment. I learned this the hard way...

--
Ron Ramirez
Ferdinand IN
#5

I have been using clear GE silicone sealant/glue type adhesives ( GE type household glue) for over 20 yrs to re-attach the old orig wax-coated loop antennas back to their orig positions when loose. Not saying using it effects direct contact with copper? I dunno,.. but the sets loop-antennas I repaired over 20 yrs ago are still working fine on all my sets. I have repaired 100s of those type vintage litz-wire, & solid small- copper wire loop type antennas. No orig "litz-wire" cloth deterioration at all in those many yrs-ago since application of the silicone, and I still use it when the need calls for it. Once those orig loop antenna wires are "sealed", and attached to the rear cover, etc, with the silicone, they stay "put" forever.
No signal-strength "gain or loss" for orig loop antennas whatsover after applying the clear silicone adhesives in my yrs of using it. You can apply it while listening to your favorite-distant stations, and no change in reception at all. As "Brill-Cream" use to advertise, "just a little-dab will do ya"!! 100% silicone-glues are non-conductive in these type applications. Has worked for me Many times with no remorse whatsoever.
There is probably something better to use? Im always open for better type suggestions indeed. I learn something new everyday working on these old tube type radios!

While were on the subject of using silicone adhesives in the vintage radio repairs, another "tip"... is that the "fast drying" Black color (gasket sealers) avail in a hand-held tube works great for repairing torn Spkr Cones also!! You can get it at any local Auto Parts Stores or WalMart automotive supplies area. It dries fast, is flexible, and always moisture-proof once applied. I have saved many vintage spkrs using it over the yrs also. Careful application is required indeed!!

JB Weld is also very forgiving when forming new (metal-type) parts replacements, or attaching metal-to-metal parts on vintage radios including control-shafts extensions,etc when necessary! It is also non-conductive? Ive never been able to get a "continuity-test" across it before! Just sharing some tips that have always worked well for me. Icon_wink
#6

Sorry Randal, but I have to disagree when it comes to the use of silicones in electronic equipment...

I used to use silicone to seal Philco tone controls and those small rectangular metal case condenser cans that mount with two tabs. I stopped when a customer returned a set because it had stopped working. The fault was traced to...a metal case condenser sealed in silicone that had failed. That day I switched to hot glue for tone controls, and to hold caps in place in those metal case condensers.

Another tech told me some time ago some horror stories of how electronic parts that had been sealed in silicone would later fail...and how the silicone had caused the failure by eating through the copper.

In addition to all this...black silicone may be OK for going around the perimeter of a speaker cone, but you should be aware that some black silicones have conductive material in them! A certain Philco (non) "expert" used to fill all of his bakelite blocks with this stuff, and he swore it was great. (Chuck knows who I am referring to, and no, it is not Chuck!!!) It's unbelievable to me. I would hate to be the one having to troubleshoot some of his radios later when they mysteriously failed!

(As a side note, there is no reason whatsoever to reseal a bakelite block once it has been rebuilt. It is a waste of time. No-one is going to look into them, and besides, by leaving them unsealed, you have made things easier for the next tech who may have to rebuild it again in another 50-75 years.)

Now, when it comes to JB Weld, I can agree that it is a true asset to any serious radio restorer. Icon_smile

--
Ron Ramirez
Ferdinand IN
#7

So, aside from the possible questionable suitability of using silicones, what are other suitable choices I can use?

Did I gather 'hot glue' is an alternative?

Any other suggestions?

John
#8

DUCO cement, perhaps? I'd stay away from the really permanent things like epoxy or superglue because the loop may need to be removed.
#9

I had thought of Duco, but wondered if the solvents in it would disolve the coatin on the antenna wire. I don't remember what that coating is supposed to be or if it's susceptible to those solvents, not to mention the inside of the bakelite case! Xylene, Acetone, MEK and the like are some nasty solvents. I do know that!
#10

Im no "expert" on anything in life! Except interior housepainting these days!! (hee hee)! I however can share my past experiences where I have used silicone-adhesives successfully in the past 20 yrs on vintage radio electronics related issues. The "clear" type silicones have never-ever been a bad choice for me in loop-type antenna repairs. My sets still work just as I repaired them many yrs ago, " many orig ant-loops" saved , and still located where I placed them, on old cardboard type rear radio panels or etc. to hold them in place. Just worked for me for over 20 yrs or so, so I thought sharing my experiences could be considered as a "option" only.
As far as using silicone type adhehives to seal vintage Philco tone-controls,etc, wouldnt be a good choice at all from the get-go.
The black silicone sealants do work well on simple spkr-cone repairs also.
I would never even think about "re-stuffing" orig bakelight style- condensers, paper tube condensers, or etc metal metal-type condenser enclosures in any radio period,"from AK to Zenith ...A-Z"... especially using silicone, "hotglue" or anything to just to try to save "originality"! What a waste of time!! I have never had bad results using silicone adhesives when used properly in applications on vintage radios.
I have over 50 vintage radios here in stock, using clear silicone adhesives to re-attach the "loop style" antennas, & I will put my vintage receivers sets up to a DX contest! (hee hee)
Dont let silicone adhesives become a "threat" in your vintage radio restorations at all!! Just dont use it to seal "tone controls",.. vintage bakelight caps etc!! For simply using to "re-attach" a good vintage loop-antenna back in place, "git-r-done"!! No remorse whatsoever!! Im not a "purist" when it comes to re-stuffing-caps, etc,... I prefer new ( well marked) chassis parts mounted to new terminal-strips, as opposed to re-using the orig bakelight, or metal type condenser housings! Thats just me, and I certainly dont expect for all to agree w/ me at all !! I just share on these pages what works well for me in my repair-shop. It kinda comes down too: "whatever blows up your shorts" on opinions? Reckon? Im always open to better-suggestions also, but I wont be "re-stuffing" any old capacitors! That way, just as Ron suggested, leaves all new components ( we all add these days) will be installed in easy "view" for the next tech 75- 100 yrs from now when all us discussing this issue here are long-gone. Me "no-scare" using silicones properly!! Icon_wink
#11

phly guy Wrote:I had thought of Duco, but wondered if the solvents in it would disolve the coatin on the antenna wire.

I use it often with enamelled wire with no problem. There's also a Duco Model Cement and I think it would be ok too. Regular Testor's model cement doesn't harm the enamel.

GL,
Bill




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