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AE 40, 47 & 50 Base Code Observations (2017!)

Started by RotoTech99, January 03, 2017, 12:13:37 PM

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unbeldi

#300
Here is an example that shows that there certainly ismay be some kind of time correlation of the two-letter codes.

N 4022 A0 NH7;  decal D-780504 A7
N 4023 B3 NH7;  decal D-780504 A3

Both phones have the same code "NH7", but different type numbers (4022 and 4023), and different decals (A7 and A3)

A 4022 is a common battery telephone with a dial, while the 4023 has no dial patents listed on the A3 label, consistent with the code B in "B3". I have found at least some 4023-type sets to be local battery sets.  The last patent year for both labels is 1942, but they both show the postal zone Chicago 7, and therefore the labels, and the phones by inference, are from 1943 or later.  So this places the NH code in that time.

I have listed another set,  L 4123 E20 NF-7, which has a A41 issue label, which is from much later (>1952), but the code NF would perhaps indicate a date just a little bit earlier than NH.

If the codes roll over this might indicate a roll over period of about 10 years.
But this is just all speculation at this time.

AE_Collector

#301
Interesting observations on the (possible) date codes. It would seem odd that they would roll the codes over in only 10 years but it could be.

By the way, I moved all of the Orchid AE40 discussion to a separate topic here:

http://www.classicrotaryphones.com/forum/index.php?topic=17673.0

Terry

unbeldi

Here is a confirmation of the first ringer code, such as in A1 or E1, which designates a ringer for a frequency of 16 2/3 Hz.

http://www.classicrotaryphones.com/forum/index.php?topic=2569.0




unbeldi

#303
Here is a summary of ringer codes, including the order numbers for the ringers ca. 1950.

The first column is the code used in formats (e.g. Ax, Ex) such as this: L 5000 E1

and the second column is for format as in: L 4123 A33

Low impedance ringers by AE were only available in nine frequencies, plus the SL version.

PS:  I don't actually recall having seen the code 17 for a 16 2/3 Hz ringer, so this is a bit of speculation, but I believe I have seen code 67.

AE_Collector

That's a good confirmation of the frequency/code. Typical of AE, "let's use single digits to represent each of the different ringers". Then they add some more frequencies so "let's do what we should have done in the first place - use two digits to represent the actual frequency". Then at yet another board meeting someone says "you know, we haven't used letters to indicate frequency yet, when can we start?"

I will check my records to see if I can find any 17's. And shouldn't 66.6 be 67? So there is actually a 66 and a 66.6? I sort of though one would have done both jobs since they wouldn't each be used on the same party line being two different types of systems.

Terry

unbeldi

Quote from: AE_Collector on February 18, 2017, 11:25:07 PM
That's a good confirmation of the frequency/code. Typical of AE, "let's use single digits to represent each of the different ringers". Then they add some more frequencies so "let's do what we should have done in the first place - use two digits to represent the actual frequency". Then at yet another board meeting someone says "you know, we haven't used letters to indicate frequency yet, when can we start?"

I will check my records to see if I can find any 17's. And shouldn't 66.6 be 67? So there is actually a 66 and a 66.6? I sort of though one would have done both jobs since they wouldn't each be used on the same party line being two different types of systems.

Terry

I did list 66.6 as code 67.
Yes, 66 and 66.6 Hz were distinct types, technically.
66 was for the synchromonic system (54 + 12), and 66 2/3 (50 + 16 2/3) was for the harmonic system.



unbeldi

#306
AE's list of frequencies appears to suggest that they did not support the decimonic ringing system for low-impedance ringers.  But they did have a 20 Hz frequency ringer. The decimonic system is the only one that  used it.

I believe AE used it in place of the 16 Hz ringer for the synchromonic system.

The 16 Hz ringer for the synchromonic system was a compromise anyways, because it does not strictly fit into the synchromonic series, where it should have had the frequency 18 Hz  (30 Hz – 12 Hz), but 18 Hz is exactly one third of 54 Hz, and therefore such a ringer combination would be subject to cross-ringing by harmonic resonance, the very problem that the synchromonic system was supposed to avoid.  As a solution, they (Leich or Kellogg) lowered the frequency from 18 Hz to 16 Hz to throw it off-resonance.  Apparently, AE chose to go the other way and increase it to 20 Hz.

It should also be noted that the low frequency (16 Hz) was not originally part of the synchromonic system at all, as the ringing systems originally only used four frequencies instead of 5.

I would like to find reliable references to this theory, if anyone has any, please reply, pro or contra.

For reference:

Harmonic: 16 2/3, 25, 33 1/3, 50, 66 2/3 —> 1, 2, 3, 4 times 16 2/3
Synchromonic:16 (18), 30, 42, 54, 66—> (3), 5, 7, 9, 11times 6
Decimonic:20, 30, 40, 50, 60—> 2, 3, 4, 5, 6times 10

Blue numbers indicate the frequencies not originally present in the system.
A possible reason for not supporting the decimonic system is that it also has harmonic conflicts: 20/40/60, 30/60





AE_Collector

#307
Quote from: unbeldi on February 19, 2017, 08:53:02 AM
AE's list of frequencies appears to suggest that they did not support the decimonic ringing system for low-impedance ringers.  But they did have a 20 Hz frequency ringer. The decimonic system is the only one that used it.

I believe AE used it in place of the 16 Hz ringer for the synchromonic system.

Was the Decimonic System designed to work with low impedance ringers (only) or did AE appear to not support it for low impedance ringers but did support it for high impedance ringers? The former I assume.

For what it is worth, I was never in a situation where I was taught any of the details of the various systems, I only learned the basics of frequency ringing as part of basic telephony. I worked for awhile in an AE SxS office in a semi rural area that had numerous party lines up to 10 parties I believe. From what I saw and learned in that office I thought at the time that party line frequencies were 20, 30, 42, 54 & 66 CPS. So this supports your theory about AE and Synchromonic Ringing though I don't know that I have any documentation about it.

Presumably the system that a CO uses is determined by the ringing machine installed which was probably picked by an engineer to be a good fit for the office. Number of parties required on a line would be a factor. Would other factors such as potential lengths of the lines be a factor as well or more likely the types of subs equipment generally used in the area?

Terry

Quote from: unbeldi on February 19, 2017, 08:53:02 AM
For reference:

Harmonic: 16 2/3, 25, 33 1/3, 50, 66 2/3 —> 1, 2, 3, 4 times 16 2/3
Synchromonic:16 (18), 30, 42, 54, 66—> (3), 5, 7, 9, 11times 6
Decimonic:20, 30, 40, 50, 60—> 2, 3, 4, 5, 6times 10

Blue numbers indicate the frequencies not originally present in the system.
A possible reason for not supporting the decimonic system is that it also has harmonic conflicts: 20/40/60, 30/60

unbeldi

I made one error of omission in my previous table of frequencies.

It should have been the following, adding the multiplier 1.5 for the 25 Hz entry in the harmonic system.


Harmonic: 16 2/3, 25, 33 1/3, 50, 66 2/3 —> 1, 1.5, 2, 3, 4 times 16 2/3
Synchromonic:16 (18), 30, 42, 54, 66—> (3), 5, 7, 9, 11times 6
Decimonic:20, 30, 40, 50, 60—> 2, 3, 4, 5, 6times 10




Quote from: unbeldi on February 19, 2017, 08:53:02 AM
For reference:

Harmonic: 16 2/3, 25, 33 1/3, 50, 66 2/3 —> 1, 2, 3, 4 times 16 2/3
Synchromonic:16 (18), 30, 42, 54, 66—> (3), 5, 7, 9, 11times 6
Decimonic:20, 30, 40, 50, 60—> 2, 3, 4, 5, 6times 10

Blue numbers indicate the frequencies not originally present in the system.
A possible reason for not supporting the decimonic system is that it also has harmonic conflicts: 20/40/60, 30/60

unbeldi

#309
Quote from: AE_Collector on February 19, 2017, 11:49:56 AM
Was the Decimonic System designed to work with low impedance ringers (only) or did AE appear to not support it for low impedance ringers but did support it for high impedance ringers? The former I assume.
If anything, it appears that the decimonic system perhaps was used for high-impedance ringing. I don't have a specific time when the system appeared.
Interestingly, though, the Kellogg catalogs of ca. 1940 only list two of the decimonic frequencies.

Quote
For what it is worth, I was never in a situation where I was taught any of the details of the various systems, I only learned the basics of frequency ringing as part of basic telephony. I worked for awhile in an AE SxS office in a semi rural area that had numerous party lines up to 10 parties I believe. From what I saw and learned in that office I thought at the time that party line frequencies were 20, 30, 42, 54 & 66 CPS. So this supports your theory about AE and Synchromonic Ringing though I don't know that I have any documentation about it.
Thanks, indeed.

unbeldi

This AE 35 Monophone provides the confirmation of ringer code 8 being for 42 Hz.

http://www.classicrotaryphones.com/forum/index.php?topic=12961.msg136771#msg136771


unbeldi

#311
Not exactly "base" codes anymore, but highly related, I expanded the previous list into a cross reference table.

A few columns can probably still be added, namely for the 34A3A (ca 1939) and for the AE 40 and 50s in the 1940s.
I only have those as a listing in terms of those abbreviated catalog numbers, that are useless for us, because the ringers were always marked with order numbers, not the catalog numbers.

So we have to compile the remaining ringer numbers from observations, in case they are different than what I already listed.
I do think the 34A3A ringers are different because they needed to lay flat on the base, rather than being mounted at an angle.

When going through the catalogs, it is interesting to note that AE never uses the term synchromonic, they just call them harmonic.  That even later, when they do distinguish decimonic ringers as such.


[updated]

AE_Collector

Quote from: unbeldi on February 18, 2017, 05:56:04 PM
PS:  I don't actually recall having seen the code 17 for a 16 2/3 Hz ringer, so this is a bit of speculation, but I believe I have seen code 67.

I have records of the following "two digit" ringer codes from Telephone Base Codes of 40's and 50's:
20
25
30
33
50
54
66
67

Terry

AE_Collector

Quote from: unbeldi on February 19, 2017, 05:30:00 PM
This AE 35 Monophone provides the confirmation of ringer code 8 being for 42 Hz.

Interesting that they put both the 8 and the frequency 42 on that Base Code.

Terry

unbeldi

#314
Quote from: AE_Collector on February 20, 2017, 11:49:24 PM
Interesting that they put both the 8 and the frequency 42 on that Base Code.

Terry
Usually the frequency is only stamped on the schematic insert.

I should probably change the 17 back to 16, because the replacement ringers of 1958 list it as -A16R, while showing the 66.6 Hz ringer as -A67R.
Since there was no need to distinguish it from 16 (unused by AE) they probably just used 16.
Interesting that you haven't found either one, 16 or 17, perhaps it was used only rarely in AE country, or perhaps not at all by your experience.

But someone was using it, as that schematic with 16.6~ printed on it documents.