Seeburg Pulse Amp
 

Hi all,
I've searched the group for info on the Pulse amp (in my AY160)
causing selection problems. I've also followed the troubleshooting
guide and have located ther issue as being the pulse amp (or so I
think!)
I've changed the cap in the unit and still no joy, someone has worked
on this before as the 5m resistor is made up of 4 other restistoes but
it comes to almost 5m.
There is a small ferrite coil in there, looks like a transformer /
choke and its busted up but it would appear that the windings are
still ok.
Anyone got any idea what that does and will it work if the case is
broken?
Any thoughts welcome
Cheers
Shaun

While the coupling capacitor in the pulse amp is *usually* the culprit in the
case of selection problems, the resistors run a close second. If you've
replaced the capacitor and still have problems, I'd recommend replacing *all*
the resistors in the pulse amp, as I've found they tend to degrade due to the
heat inside the pulse amp chassis. The pulse amp is somewhat sensitive to
variations in component values.

Other problems external to the pulse amp are the 56k and 470k resistors under
the chassis that connect to the pulse amp and 2050 tube sockets, and the
coupling capacitor that connects to the pulse amp socket. If you pull the
12AX7 tube out of the socket while the mech is scanning, does the mech trip
and switch into transfer/play mode? If so, the problem is likely isolated to
the pulse amp itself. If not, you have more extensive work to do.

You can purchase replacement resistors from mail-order sources such as Mouser
Electronics (www.mouser.com).

Joseph "Tony" Dziedzic

In article ,
(shaun) wrote:
Hi all,
I've searched the group for info on the Pulse amp (in my AY160)
causing selection problems. I've also followed the troubleshooting
guide and have located ther issue as being the pulse amp (or so I
think!)
I've changed the cap in the unit and still no joy, someone has worked
on this before as the 5m resistor is made up of 4 other restistoes but
it comes to almost 5m.
There is a small ferrite coil in there, looks like a transformer /
choke and its busted up but it would appear that the windings are
still ok.
Anyone got any idea what that does and will it work if the case is
broken?
Any thoughts welcome
Cheers
Shaun

Thanks for the info, I'll do the resistors as well then, when I pull
the tube it doesn't trip so you reckon that may indicate work outside
of the pulse amp? I've not looked inside the chassis that the pulse
amp connects to, I wanted to get it selecting before I started the
restoration but maybe I should just replace all caps and check all
resistors and see how it goes post restoration
Cheers
Shaun

(Joseph A. "Tony" Dziedzic) wrote in message news:JpHMa.20541$926.833@sccrnsc03...
While the coupling capacitor in the pulse amp is *usually* the culprit in the
case of selection problems, the resistors run a close second. If you've
replaced the capacitor and still have problems, I'd recommend replacing *all*
the resistors in the pulse amp, as I've found they tend to degrade due to the
heat inside the pulse amp chassis. The pulse amp is somewhat sensitive to
variations in component values.

Other problems external to the pulse amp are the 56k and 470k resistors under
the chassis that connect to the pulse amp and 2050 tube sockets, and the
coupling capacitor that connects to the pulse amp socket. If you pull the
12AX7 tube out of the socket while the mech is scanning, does the mech trip
and switch into transfer/play mode? If so, the problem is likely isolated to
the pulse amp itself. If not, you have more extensive work to do.

You can purchase replacement resistors from mail-order sources such as Mouser
Electronics (www.mouser.com).

Joseph "Tony" Dziedzic

In article ,
(shaun) wrote:
Hi all,
I've searched the group for info on the Pulse amp (in my AY160)
causing selection problems. I've also followed the troubleshooting
guide and have located ther issue as being the pulse amp (or so I
think!)
I've changed the cap in the unit and still no joy, someone has worked
on this before as the 5m resistor is made up of 4 other restistoes but
it comes to almost 5m.
There is a small ferrite coil in there, looks like a transformer /
choke and its busted up but it would appear that the windings are
still ok.
Anyone got any idea what that does and will it work if the case is
broken?
Any thoughts welcome
Cheers
Shaun

Given the age of an AY160, I would HIGHLY recommend you completely rebuild the
tormat selection receiver chassis before running the unit. The huge power
transformer on that chassis can be toasted by leaky filter capacitors inside
the receiver chassis, and it's hard to find a replacement for that
transformer.

One note - the tormat receiver is a POSITIVE GROUND design - that means the
filter capacitors have their POSITIVE lead connected to ground, which is
opposite of most tube-type electronic equipment. I've seen a few cases where
folks have replaced those and accidentally reversed polarity - not a pretty
sight as the filter cap explodes!

Joseph "Tony" Dziedzic

In article ,
(shaun) wrote:
Thanks for the info, I'll do the resistors as well then, when I pull
the tube it doesn't trip so you reckon that may indicate work outside
of the pulse amp? I've not looked inside the chassis that the pulse
amp connects to, I wanted to get it selecting before I started the
restoration but maybe I should just replace all caps and check all
resistors and see how it goes post restoration
Cheers
Shaun