Thordarson or holldarson

[timmy]

Are these 2 flyback companies the same having the same item made the same. Because some flybacks have wax donuts and others have the newer plastic and silicone donut’s

[bhegges]

I have wondered the same question. I had tried searching for acquisition information but could not find anything. My guess is that at some point Thoardarson purchased Halldorson, they shared part numbers but still kept separate branding.

[Electronic M]

ISTR some Sam's where the parts sub list had a single Thordarson/Haldorson column with a single number for both brands, but maybe I'm remembering wrong.

[zeno]

Best way to tell is by EIA numbers on the part.
EIA #'s are one to 4 place numbers with each mfg having a ##.
Example is #343 for Zenith. It can be any brand but if you see
#343 on the CRT you know Zenith built the CRT.
Other info you can find on parts is.

Week & year date codes, 4 places. example 4578 is 45th week, 1978.
OEM part ##'s.
MFG part ##'s .
Run ##'s
Values.
All can be useful ! AND fun

Now someone that has the list of EIA ##'s please post. I cant find it any more. I knew many but age is slowly eating away at my brain list !

73 Zeno
LFOD !

[sean]

There are a few lists of EIA codes at this site:

https://www.ecianow.org/eia-source-codes

I found Gramer-Halldorson listed with an EIA code of 596. Thordarson's EIA code is 238.

It's interesting that they used very similar graphics on their boxes (from eBay auctions):

[zeno]

TNX 4 that link Sean. I saw that box & said "boy that looks like a Thordarson box !". Aah the memories.
When I scrolled down any doubt about it went away.

73 Zeno
LFOD !

[bhegges]

1. To the original question of waxed dipped vs plastic/silicone I assume that was an industry best practice change over time instead of a Thoardarson vs Halldorson difference in construction
2. Were these company partners or one a sub-division of the other or did they just share common aftermarket part numbers?

[old_tv_nut]

The switch from wax to silicone could have been due to a change in UL requirements.

[Electronic M]

It seemed to be an over time change to me. There was an in-between time where vulcanized rubber was used...It had a tendency to become conductive and cause arc overs on CTC-16 and later RCAs.

[Yamamaya42]

Originally Posted by Electronic M

It seemed to be an over time change to me. There was an in-between time where vulcanized rubber was used...It had a tendency to become conductive and cause arc overs on CTC-16 and later RCAs.

As anyone can tell you, klingonized is always better!

[Electronic M]

Originally Posted by Yamamaya42

As anyone can tell you, klingonized is always better!

Lol.