It's economics, surely to large degree.
Note I didn't say there was a flaw in functionality, on the face of it. There's a difference in method, the majority of modern offerings are not 'same as'. It leads in to the same morass as any discussion about the realism of clones.
Some data I did write down, not a lot directly apples to apples, but enough to make general trend observations and supported by all the other measurements I've taken but not written down. All of these are averages of multiple units, so not unconfirmed single outliers.
I've noted various things at 120Hz, L, sometimes ACΩ, sometimes DCR, quoted Z. In general, higher L and DCR equates to lighter ACΩ loading. None of it says anything definite about bandwidth or frequency linearity.
One example, it's extremely rare to see a modern mic/line to grid transformer with a secondary DCR over 3K, in old stuff it's normal to see 4K-7K.
some outputs of various types
Sowter 8344E - Fairchild signal output 60K:600
32h, 90k ACΩ, 510 DCR - you would expect 5-10x these numbers in an older transformer
1040mh, 320 ACΩ, 5R5 DCR
- not the H is still a fraction of the lowest below, the lowly Peerless 15095.
UTC LS-50 (SE)
15K 645h 328k ACΩ, : 500 20.3h 13k9 ACΩ
UTC LS-51 (PP)
30K 2487h 856k ACΩ : 500 34.57h 13k9 ACΩ
Gates SA-70
15k 477h 186k ACΩ : 500 16.38h 11k ACΩ
Collins 6Q-1
15k 287h 156kACΩ : 500 13.58h 9k9 ACΩ
Peerless 15095
179h 55k ACΩ : 9.5h 4k75 ACΩ
Various RCA single ended DC coupled outputs 30-50K : 250-500
240-250H : 3-5H5
Some interstages note the Hammond 850Q test, source and load Z of 40K with full bandwidth
Sowter 9830 BA-6 interstage DCR 1680Ω, recall approx 200H +36 rating! Why?!?!
Hammond 835 10K/40K:” +/- 0.5db 50-15K +15dbm, 0mA unbal DC, 980:982H
Hammond 850Q 10K/40K:” +/- 0.5db 20-20K +15dbm, 0mA unbal DC, 1400-1685:1400-1685H (40K:40K) 480K AC Ω 5K DCR
looks the same connected either side to ground, 40K source and load yields
+/-1dB 10.9-29K4Hz rising 34K9 peak +1.5dB
+/-0.5dB 16.8-26K5Hz
RCA 86-A limiter interstage 5K2ct:, 2029Hct:1023H
UTC A-18 grey badged era
1070 : 2948 DCR
246H : 1301H
321K : greater than 1M AC impedance at 120Hz
RCA 76 console program amp interstage
258H : 1605H
875 DCR : 3K08 DCR
a couple 600:600
Edcor WSM600/600
10H3 3k6 ACΩ
WE 111C
51H 19K ACΩ
Hammond 850G
12H9 10K ACΩ
UTC A-20
23H 14K AC Ω
Note I didn't say there was a flaw in functionality, on the face of it. There's a difference in method, the majority of modern offerings are not 'same as'. It leads in to the same morass as any discussion about the realism of clones.
Some data I did write down, not a lot directly apples to apples, but enough to make general trend observations and supported by all the other measurements I've taken but not written down. All of these are averages of multiple units, so not unconfirmed single outliers.
I've noted various things at 120Hz, L, sometimes ACΩ, sometimes DCR, quoted Z. In general, higher L and DCR equates to lighter ACΩ loading. None of it says anything definite about bandwidth or frequency linearity.
One example, it's extremely rare to see a modern mic/line to grid transformer with a secondary DCR over 3K, in old stuff it's normal to see 4K-7K.
some outputs of various types
Sowter 8344E - Fairchild signal output 60K:600
32h, 90k ACΩ, 510 DCR - you would expect 5-10x these numbers in an older transformer
1040mh, 320 ACΩ, 5R5 DCR
- not the H is still a fraction of the lowest below, the lowly Peerless 15095.
UTC LS-50 (SE)
15K 645h 328k ACΩ, : 500 20.3h 13k9 ACΩ
UTC LS-51 (PP)
30K 2487h 856k ACΩ : 500 34.57h 13k9 ACΩ
Gates SA-70
15k 477h 186k ACΩ : 500 16.38h 11k ACΩ
Collins 6Q-1
15k 287h 156kACΩ : 500 13.58h 9k9 ACΩ
Peerless 15095
179h 55k ACΩ : 9.5h 4k75 ACΩ
Various RCA single ended DC coupled outputs 30-50K : 250-500
240-250H : 3-5H5
Some interstages note the Hammond 850Q test, source and load Z of 40K with full bandwidth
Sowter 9830 BA-6 interstage DCR 1680Ω, recall approx 200H +36 rating! Why?!?!
Hammond 835 10K/40K:” +/- 0.5db 50-15K +15dbm, 0mA unbal DC, 980:982H
Hammond 850Q 10K/40K:” +/- 0.5db 20-20K +15dbm, 0mA unbal DC, 1400-1685:1400-1685H (40K:40K) 480K AC Ω 5K DCR
looks the same connected either side to ground, 40K source and load yields
+/-1dB 10.9-29K4Hz rising 34K9 peak +1.5dB
+/-0.5dB 16.8-26K5Hz
RCA 86-A limiter interstage 5K2ct:, 2029Hct:1023H
UTC A-18 grey badged era
1070 : 2948 DCR
246H : 1301H
321K : greater than 1M AC impedance at 120Hz
RCA 76 console program amp interstage
258H : 1605H
875 DCR : 3K08 DCR
a couple 600:600
Edcor WSM600/600
10H3 3k6 ACΩ
WE 111C
51H 19K ACΩ
Hammond 850G
12H9 10K ACΩ
UTC A-20
23H 14K AC Ω