Ami AVC H-486 / H-2260

my objective is to restore and complete my jukes as original as possible

regarding the Ami F120 I found an AVC

info when it comes to this AVC is limited :
1 : archive on this website
2: one thread on a US forum
3: website about service bulletins

left me rather confused

are the H-486 & H-2260 the same ?
when it comes to the Amp. it becomes even more confusing
bulletin 128 refers to the H-486 and an adaptor kit ( no connector on the Amp)
bulletin 134 refers to 2 seperate not interchangeable H-486's
the first and a revised one ( with a yellow dot on the casing )
also a revised Amp. for the revised H-486
are there now 3 different R-145 Amps ?
1 without connector ( adaptor kit needed )
2 with a connector ( no adaptor kit needed )
3 revised ( only the revised AVC with yellow dot )

to top this all :
my Ami F120
Amp layout in the manaul shows no connector : H-486 + adaptor kit needed
but my Amp has a connector : only H-486 ( without yellow dot ? )
as mine has a connector , is it a revised Amp? ( serial F120 is below 356400 : not revised ? )

only thing I can quess about the history of this juke is that it was most likely a direct import to Germany
(wanted the slug rejector to work , has a sticker National Rejectors department Hamburg on it , so I
bought some Germans coins and it worked - 2x 10 Pfennig / 1x50 Pfennig / 1 x 1 Mark )

who can shed some light on this issue ?

ps understanding/reading German is no problem , writing is a different story








1 mal bearbeitet. Zuletzt am 26.04.13 10:18.

Hello 24AB2

The information for the AVC unit are actually very limited. I have not even seen a diagram of it. Also on my amplifier schematics no AVC socket is shown. As far as I know, the G-200, possibly late G-80 or G-120 were first delivered with AVC. The original amplifier for the F120 had no socket for the AVC. I suspect that a newer amplifier was installed.

I do not know exactly what is done in the revision of the amplifier and if your amplifier is revised. The service bulletin refers to a circuit that applies a bias to the 10uF capacitor in the AVC. as long as the amplifier is muted. I think that a resistor (or more) near the mute switch contacts must be present for it, and an additional line to the AVC. This circuit (called "squelch" in later amplifiers)  causes the music begins to play softly.

I think you're right with the assumption that there are three different versions of the amplifier, and two versions of the AVC. Possibly the revised AVC with the yellow dot has a different part number.

Maybe someone has more information.

Best regards - charly49

Hi charly49

thx for your answer

you are right in your assumption a newer Amp. is installed
I removed the Amp , and indeed : revised june 6,1957

leaves the question about the AVC
here it's called a H-2260 : [www.jukebox-world.de]
and here a H-486 : [www.jukebox-world.de]

best regards 24AB2

Hello 24AB2

The system of part numbers of AMI is sometimes confusing. I suspect that the AVC unit received a different part number as part of the conversion kit. It is also possible that there are small changes, perhaps an additional function, which allows synchronization of the two AVC - units in stereo mode. Stereo Js are very rare, and unfortunately I have never observed if there are differences.

Best regards - charly49

Hello 24AB2,

I also do not know much about these AVC.
So I checked the manuals but unfortunately AMI did not publish an extra sound sytem parts catalog with each model.
There is one for model G200. But for both models H and J parts catalog from AMI I has to be used. This makes it more difficult to find out more.

Parts catalog G200 does not show the AVC.
In Parts catalog AMI I the AVC is called H-486.
And H-2260 is given in the AMI J brochure.

I checked our service bulletins for AMI, too, and also found three different ones.
For everybody I scanned and uploaded them: [www.jukebox-world.de]

1st one dated Aug 2, 1956: AVC is called "Volume Compressor" which can be attached to the R-145: It is stated that an update for easier attachment will be provided soon.

2nd one dated Nov 20, 1956: this describes the amp modification charly49 did write about.
The current built H-486 will not work with this revised amp and a new AVC will be provided soon. This new AVC will become the one with the yellow dot and can be plugged directly into a socket of the R-145 amp.
Those without and with yellow dor are not interchangeable.

3rd one dated Oct 23, 1958: this does let us know about using the latest AVC with those R-145 amps not having the built-in AVC socket.


We do not know when exactly the yellow dot AVC was introduced - somewhen between 11/1956 and Oct/1958. Maybe when the schematic was revised - 6/1957?

AMI I sound system parts catalog was probably printed with introducing model I in 2/1958. In this manual the AVC is still called H-486. As the yellow dot AVC was already announced in 11/1956 I guess it was existing earlier than 2/1958. So the number H-2260 must have come later than introducing AMI I. At least this is my guess.

Actually it does not make any sense but who knows: maybe with introduction of stereo (= 2x R-145) they changed the model number to H-2260?
I could not find more about this number.

Your AMI was probably imported by the German company Rehbock, Hamburg. They imported AMIs back then.


Hildegard Stamann

Thx for all the efforts

do you know if from the 57 revision of the Amp there were more revisions ?
for if there were none this would mean the H-2260 is the same as the H-486 with the yellow dot

24AB2

Hello 24AB2,

no, I don't know if another revision was done.
Unfortunately no later sound system service manual than for G-200 was published by AMI and the bulletins do not show any.

So far we only know of the amp schematic printed in G200 service manual and the revised one like yours dated June 1957 which could be found in AMI I models, too..

Maybe somebody with an AMI J can tell if there was another revised version of the amp schematic in that jukebox.


Hildegard

started this topic because I found a H-2260 on Ebay
also found a H-486 ( with yellow dot )

uploaded pictures

ok, this is a wild quess
but I think there is a difference

the 2260 seems to have 3 noticeable wires
the 486 also 3 , but 1 wire has (as it is bigger ) probably bundled wires

Hello 24AB2

I think there are many more than three wires existing in all versions. 2 wires are needed for the tube heating, 1 wire for the plate voltage, 1 wire for ground and one wire for each signal input and output. These are 6 wires together. An additional wire for the squelch function is still required for the revised version, and certainly also for the H2260. If you look at the schematic, you see that all 7 pins of the AVC socket are connected.

So there should be no difference in the wiring. There may be small differences in the AVC unit. I suspect that already produced H-486 were later rebuilt and were marked with the yellow dot. As these converted units were sold, had to be reproduced and it was assigned a new part number.

Best regards - charly49

bought the AVC ( with yellow dot ) 1 week ago
( thought it was the best option with my Amp. )
arrived today , and as it is with new toys I plugged it in ( after checking it out )

and it actually works !!!!

conclusions :

don't know a lot when it comes to Amps and related things
but what it does is dampening the volume and probably leveling it

was it worthwhile ?
for me : yes , because I try to make my jukes as complete as possible
in general : no , doesn't add that much so one might ask is it worth the investment

as it still has all the original caps I need to replace those
that should be no problem
but on 1 ( if it is a capacitor ) the values are not readable anymore
( the white one : see pictures )

anyone ?

24AB2

ps at the time I replace the caps I will try to make a schematic ,so it can be compared to the other models






1 mal bearbeitet. Zuletzt am 16.05.13 11:19.

Hello 24AB2

"Never change a winning team" already says a famous proverb. Why do you want to replace capacitors that are not broken? By exchanging capacitors - even if they have the same capacitance value - the characteristics of the amplifier are changed frequently, in most cases disadvantageous. It also happens sometimes that mistakes happen when mounting, especially if the necessary expertise is lacking. Thus, you should only replace the parts that are broken, all other you should leave.

Best regards - charly49

ok, the capacitors still seem to be in good shape ( no leaking and the AVC seems to be working ok )
but these caps are about 60 years old
are they still in the same shape as when they were new ?

the Amp is restored by a professional
and to be honest : this rather small R-145 Amp can easily match the sound of the Seeburg 100R Amp

best regards 24AB2

missing code

code : PJ6P1
600V .1mdf

Hello 24AB2

I think the age of the components is often an advantage. Previously, the parts were built for eternity. Today, the parts are produced as cheap as possible. Most of the parts produced today will certainly not survive 50 or 60 years, but many of the old parts will work another 50 years or more.

600V .1mfd means 0,1µF (= 100nF) / 600V

Best regards - charly49

Hello charly49

ok , will at first go with your suggestion ( leave it as it is )
but
have to order other parts and will order these caps also
( saves me on the posting costs incase I need them in the future and those caps are not that expensive )

perhaps these caps can be tested , will ask some-one from the technical service at my workplace

best regards 24AB2

replaced the caps

test results of the old caps

.047 mfd = 47 nF result : 75 nF
.01 mfd = 10 nF result : 26 nF
.01 mfd = 10 nF result : 30 nF
.1 mfd = 100 nF result : 138 nF
.5 mfd = 500 nF result : 1.08 uF

electrolytic caps
20 uF result : 22.6 uF
10 uF result : 10.5 uF

Hello 24AB2

The results of your measurements are not a big suprise for me.
The red caps (Tiny Chief) are also often used by Seeburg in their amps and tormat selection receivers (power supplies).
I measured hundred of them and came to the realization that they should be always replaced. Their capacity values are very often out of tolerance. They have to much leakage current and a lot of them have also a terrible bad Q-factors!

Kind regards
Roland

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1 mal bearbeitet. Zuletzt am 01.02.21 11:13.