Xicon 42TL016 value

[frets]

Hello Great Sentries of Guitar Erudition,

I got excited by a low price and bought a lot of Xicon 42TL016 Audio Signal Transformers. Their blue color fooled me into thinking they were the exalted 42TL021’s. Alas, they are not. They’re big chunky transformers that I can not discern the amount of Henries. I can find no chart that has them listed; and, my LCR meter is giving me odd readings that can’t be correct. Does any brother out there know of the H value of these impersonators?

[thetragichero]

sounds like maybe a measurement issue? are you using alligator clip leads to secure the lcr meter leads to the transformer leads?

[newey]

Yeah, I kinda thought this was the point of springing for that LCR meter in the first place . . .

Probably a stupid question, but after you got the odd readings, did you try the meter on a known-value coil?

[Yogi B]

Feb 2, 2021 16:36:29 GMT -5 frets said:

They’re big chunky transformers that I can not discern the amount of Henries.

"Big chunky" compared to a 42TL021?

Looking at this datasheet there's about 30% less total turns (primary + secondary) on the '16 than the '21 -- However the resistance values suggest that the '16 has thicker wire: '16 sec. = 55/680 ≈ 0.08088 Ohms/turn; '21 sec. = 64/440 ≈ 0.14545 Ohms/turn. That's a difference of roughly two or three AWG or an increase in wire diameter of about 30-40%. So all that being said, I wouldn't expect the things to be significantly larger than the '21 and therefore your "Big chunky" remark is surprising.

I find the impedance part of the table more than a little cryptic, presumably it gives a more accurate ratio of the coils inductance than can be had by squaring the turns ratio, but beyond that I don't know if anything more meaningful can be extracted.

[frets]

Hi Yogi,

Thanks for the information, I really appreciate the time you took to look it up for me. I figure the AST is putting out about 330mH. But it is SO Chunky. Here it is in the middle between an old 42TL018 (2.6H) and a Chinese one measuring 1.6H.

I think they are a bazillion years old.  

And I thought I was getting a deal.

[Yogi B]

I was just about to post an edit:

There is a 42TM series rated at a higher power (200mW versus 75mW) which are physically larger, and that range includes a 42TM016 part. See this eBay listing of transformers from both series -- it also appears that the 42M016 is colour-coded blue, unlike the 42L016 which thus far I've only seen in red.

Quickly looking over the datasheets it appears that other than the power rating each of the TL & TM parts are roughly equivalent in terms of their primary application as transformers, each with the same given impedance values and only minor differences to DC resistance & turn ratio. But again, I can't say much about the actual inductance values, and whether those are also equal between both series.

[frets]

Yogi,
Thanks once again, you’re always so thorough, thoughtful, mindful and most helpful to everyone you assist.

I will continue to research although I doubt I’ll find the inductance information. Mouser was no help at all (that’s who they originally came from although they’re Xicon’s). What perplexes me the most is why my meter is giving spurious readings with all of them. Trag had asked if I were using my probes and I am; however, the transformers are not cooperating.

What I’m going to do is simply put one in a circuit on a breadboard and just listen to its effect on the caps arranged on a rotary switch. I’ll AB it with a 42TL018 and a 42TL021. Perhaps they will turn out to be of a value I can use, although they still are chunky monkeys!! Thanks again Yogi. You’re the best!! 🥰

[frets]

Newey,
I did try my meter out on known value transformers. The whole thing is very odd (as am I. Ha!!). It looks to me like they’re 330mH, but they are so honking huge you’d think they’d pack more punch.