beatnik

Re: RCA BA-6A problem
« Reply #60 on: December 05, 2018, 07:23:35 AM »
I'd be tempted to put a Hammond 850Q in there.   Spec is right in all ways, L is high, and response is pretty much flat even with a 40K source and a 40K load.  A Hammond 835 would probably also work fine, though L is a lot lower. 

There's a thread about BA-6 transformers, Lassoharp and I tried and measured a bunch of different things.  Lots will work.

Quick question again on this subject
How did you find out about the inductance value of the Hammond 850Q vs Hammond 835 ? Is this something you measured ?
I haven't been able to find out that information from Hammond datasheets


EmRR

Re: RCA BA-6A problem
« Reply #61 on: December 05, 2018, 08:25:37 AM »
I measured multiple samples. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

beatnik

Re: RCA BA-6A problem
« Reply #62 on: December 05, 2018, 08:28:53 AM »
Right I see. Thank you for letting me know

Wondering if the newer 850QA is any different than the 850Q

The 850Q is now discontinued and replaced by the 850QA

The QA has wire leads instead of soldering terminals, I am wondering if the specs changed as well, might send Hammond an email and try finding out

EmRR

Re: RCA BA-6A problem
« Reply #63 on: December 05, 2018, 09:50:26 AM »
The info I've seen says the supplier of the hermetic seal headers either stopped making them or made them so expensive Hammond chose to stop using them.  Everything else should be the same.  Hammond has been making 835's about as long as the classic UTC lines were made, and I think the 850 series goes pretty far back too. 

The 850Q's I tested with a handheld meter at 120Hz ranged 1450H to 1700H on each side.   -1dB was 11Hz and around 50kHz with a 40KΩ source and 40KΩ load.  Response doesn't change a whole lot with 10K source and load, up around a half dB at 15kHz. 

The 835's landed around 1000H.   
« Last Edit: December 05, 2018, 10:02:18 AM by EmRR »
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

beatnik

Re: RCA BA-6A problem
« Reply #64 on: December 05, 2018, 10:12:13 AM »
Thanks  Doug

Re: RCA BA-6A problem
« Reply #65 on: March 13, 2019, 02:09:57 PM »
Hi everyone thanks for the kind words.

Long story short......client ordered up from Sowter before Christmas. IT got lost in a mail strike we had here in Canada before Christmas. Sowter sent a second IT that my client received. I got it last week and just clipped it in and the unit is now .....

WORKING PERFECTLY!!!!!

Now I just have to make a mount plate to fit where the original can was.

THANK YOU SO MUCH to everyone that helped - and that is everyone. Bouncing all those ideas really solved the case in the end. I couldn't have done it without you all.

Cheers and all the best.


 

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