looking for a 1N2637.... its the solid state replacement for a 866 tube

k5drc

hillbilly3302 wrote:
looking for a 1N2637.... its the solid state replacement for a 866 tube

You should be able to make your own with a couple 1N4007s and the base off
an old 866.

You should know that the series voltage drop through these things is much
less than through an 866, so your B+ will be considerably higher. If this
is a problem, you might consider adding a dropping resistor as well.

I believe that Antique Electronics Supply carries the solid state rectifier
replacements if you don't want to make your own.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

thanks for the replies... I have an old Heathkit Warrior Amp (4-811's) and
it has two of these 1N2637's in it it had some hum so I replaced the oil
filled cap. it still has a bit of hum so I figured maybe one of the
rectifiers might be bad.... need to fix it or Ill sell it as is for about
250.00 has 4 brand new 811's

Dave
k5drc

" hillbilly3302" wrote in message
.. .
looking for a 1N2637.... its the solid state replacement for a 866 tube

k5drc

hillbilly3302 wrote:

thanks for the replies... I have an old Heathkit Warrior Amp (4-811's) and
it has two of these 1N2637's in it it had some hum so I replaced the oil
filled cap. it still has a bit of hum so I figured maybe one of the
rectifiers might be bad.... need to fix it or Ill sell it as is for about
250.00 has 4 brand new 811's


Hi,

You can test a 1N2637 in any tube tester which has an 866A
tube setting. Since the "guts" of a 1N2637 has many
solid state diodes in series, a standard Ohmmeter test
won't work, since the test voltage isn't high enough
to turn the diodes on.

One item you might check in the Heath Warrior is the HV choke.
You should measure a couple of thousand a.c. volts across
it, with the High Voltage on. A shorted HV choke will result
in the increased carrier hum you describe, as well as poor
voltage regulation.

Check the 60K 100W bleeder resistor, also. An open bleeder
can be deadly.

73,
Ed k4pf

I get NO reading of anykind between the top cap and pins 1 & 4......
according to the diagram pins 1 & 4 are the cathode/ filament and the cap is
the plate.... it should read like a dioad shouldn't it?

Dave
k5drc

"Scott Dorsey" wrote in message
...
hillbilly3302 wrote:
thanks for the replies... I have an old Heathkit Warrior Amp (4-811's)
and
it has two of these 1N2637's in it it had some hum so I replaced the
oil
filled cap. it still has a bit of hum so I figured maybe one of the
rectifiers might be bad.... need to fix it or Ill sell it as is for
about
250.00 has 4 brand new 811's

If one side of those things goes open, you don't just get a little hum,
you get a hell of a lot. They don't go leaky very often but you can use
the diode setting on a multitester to make sure of that.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

hillbilly3302 wrote:
I get NO reading of anykind between the top cap and pins 1 & 4......
according to the diagram pins 1 & 4 are the cathode/ filament and the cap is
the plate.... it should read like a dioad shouldn't it?

Remember it's got a whole stack of diodes in there, each with .6V drop. So
you need to put five or ten volts across it. A lot of modern DVMs won't do
this except on the diode test function.

It's easier to put 120V through it with a 60W light bulb in series, then
measure the drop across it if you don't have the right meter.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

hillbilly3302 wrote:

looking for a 1N2637.... its the solid state replacement for a 866 tube

k5drc

The Gonset GSB 101 uses the same setup - 2 866's & 4 811's
I replaced the 866's with series strings of 1N5408's, and
added a turn on delay, because you get a pretty good surge
with the solid state rectifiers. Power to the HV xformer
is fed through a resistor for about 5 seconds, then a relay
transfers and shorts out the resistor. You don't need 3 amp
diodes (1N5408), but I was building another supply at the
same time and had them on hand.

The Gonset uses a string of capacitors, fed through a 5 - 50
swinging choke. Each cap has a bleeder across it, as I recall,
rather than a single bleeder. If the Warrior uses the same style
choke input filter, the choke could be bad. Mine was missing -
in fact the previous owner had messed with it and substituted
something different, which he did not bolt down. I bought the
thing at a scrap yard for $20.00, and all the tubes had been
smashed by that "choke". I guess it really was a swinging choke!
The crying shame is that the original problem was a bad solder
joint to the caps. I surmise that the previous owner mis-diagnosed
the problem as a bad choke and tried substituting various filament
transformers for the choke.

In any event, that choke takes a helluva surge when the solid
state diodes suddenly conduct upon power on. So you may want
to include a soft start circuit, once you diagnose your hum
problem. While you're at it, check the bleeder resistor(s)
and replace as needed. I'd recommend using 2 parallel resistors
to replace each bleeder in your Warrior, if you have the
room. Use the same wattage and twice the resistance of the
bleeder you are replacing for each new resistor, effectively
doubling the wattage. Also, you should form the capacitor(s).
I'm assuming the replacement cap has been on the shelf for a
long time. I formed mine by powering the amp from a variac,
and over the course of 24 hours raised the voltage in 10 volt
increments every couple of hours until I went from 10 volts to
120.

Good luck - it's nice to get these old beasts up to snuff.

hillbilly3302 wrote:

looking for a 1N2637.... its the solid state replacement for a 866 tube

k5drc

The Gonset GSB 101 uses the same setup - 2 866's & 4 811's
I replaced the 866's with series strings of 1N5408's, and
added a turn on delay, because you get a pretty good surge
with the solid state rectifiers. Power to the HV xformer
is fed through a resistor for about 5 seconds, then a relay
transfers and shorts out the resistor. You don't need 3 amp
diodes (1N5408), but I was building another supply at the
same time and had them on hand.

The Gonset uses a string of capacitors, fed through a 5 - 50
swinging choke. Each cap has a bleeder across it, as I recall,
rather than a single bleeder. If the Warrior uses the same style
choke input filter, the choke could be bad. Mine was missing -
in fact the previous owner had messed with it and substituted
something different, which he did not bolt down. I bought the
thing at a scrap yard for $20.00, and all the tubes had been
smashed by that "choke". I guess it really was a swinging choke!
The crying shame is that the original problem was a bad solder
joint to the caps. I surmise that the previous owner mis-diagnosed
the problem as a bad choke and tried substituting various filament
transformers for the choke.

In any event, that choke takes a helluva surge when the solid
state diodes suddenly conduct upon power on. So you may want
to include a soft start circuit, once you diagnose your hum
problem. While you're at it, check the bleeder resistor(s)
and replace as needed. I'd recommend using 2 parallel resistors
to replace each bleeder in your Warrior, if you have the
room. Use the same wattage and twice the resistance of the
bleeder you are replacing for each new resistor, effectively
doubling the wattage. Also, you should form the capacitor(s).
I'm assuming the replacement cap has been on the shelf for a
long time. I formed mine by powering the amp from a variac,
and over the course of 24 hours raised the voltage in 10 volt
increments every couple of hours until I went from 10 volts to
120.

Good luck - it's nice to get these old beasts up to snuff.