Does anyone know where these might be available for a "reasonable" price?
The cheapest I've found them for is $45 for a used "pull". I have a nearly
new 2-01C in my ME26D/U but that won't fit in the probe in my HP410B. As I
understand it, some 410B probes came with 2-01C diodes and some came with an
EA53 probe and the two are not always interchangeable.

Thanks,

Barry - N4BUQ

$45 for EA53 is reasonable price, the tube is rare. HP initially
rolled out 410B VTVM with 2-01C based AC probe but the contact with the
tube in the probe was unreliable, customers complained, and HP
eventually converted the probe by supplying overhaul kits for EA53
tubes.

Contact me off line, I have EA53's, 2-01C's, conversion kits for EA53,
and the probe assembly for 2-01C so I may be able to help you.

Jiri Placek
Boyertown, PA

Barry wrote:
Does anyone know where these might be available for a "reasonable" price?
The cheapest I've found them for is $45 for a used "pull". I have a nearly
new 2-01C in my ME26D/U but that won't fit in the probe in my HP410B. As I
understand it, some 410B probes came with 2-01C diodes and some came with an
EA53 probe and the two are not always interchangeable.

Thanks,

Barry - N4BUQ

Barry wrote:
Does anyone know where these might be available for a "reasonable" price?
The cheapest I've found them for is $45 for a used "pull". I have a nearly
new 2-01C in my ME26D/U but that won't fit in the probe in my HP410B. As I
understand it, some 410B probes came with 2-01C diodes and some came with an
EA53 probe and the two are not always interchangeable.

Have you considered a silicon diode and a filament resistor? I know it
isn't original, but it will work just fine.
--scott


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

Scott Dorsey wrote:
Barry wrote:
Does anyone know where these might be available for a "reasonable" price?
The cheapest I've found them for is $45 for a used "pull". I have a nearly
new 2-01C in my ME26D/U but that won't fit in the probe in my HP410B. As I
understand it, some 410B probes came with 2-01C diodes and some came with an
EA53 probe and the two are not always interchangeable.

Have you considered a silicon diode and a filament resistor? I know it
isn't original, but it will work just fine.

Actually, no it won't.

The tube in the AC probe is very special. It extends the frequency response
from 20Hz to 750MHz, and up to 300VAC from 20Hz to 100MHz. You won't be able
to do that with any single solid state component.

-Chuck Harris

On Wed, 17 May 2006 13:30:10 -0400, Chuck Harris
wrote:

Actually, no it won't.

The tube in the AC probe is very special. It extends the frequency response
from 20Hz to 750MHz, and up to 300VAC from 20Hz to 100MHz. You won't be able
to do that with any single solid state component.

-Chuck Harris snip

Chuck's correct on this. I used 410Bs for years, and what he says is
absolutely true on this probe. The tube is a "must have" in order to
restore full functionality to this meter. Messed up probes are the #1
reason than many otherwise good 410Bs get junked, which is a shame.
It's really a very versatile, accurate instrument when functioning
properly.

Does anyone care to comment on the differences between the ME26D/U and
the HP410B? I have both and by far prefer the 410, but I wonder if my
ME26 is working properly. It was a NOS meter when I removed it from
its box a couple of years ago and looks nearly new; however, measuring
AC with it isn't nearly as "pleasant" as my 410 was. The meter is very
"jumpy" and overloads on the lower ranges simply by picking up the
probe. It settles back down, especially when the ground clip is
attached properly to whatever is being measured, but I don't remember
the 410 acting like this. Is this due to the 2-01C or just different
components and construction methods between the two models. The ME26
is supposed to be the militarized version of the HP410B, but it does
seem to behave differently.

Barry - N4BUQ

"Messed up probes are the #1 reason than many otherwise good 410Bs get
junked, which is a shame."

My response might offend the purists, but I can defend myself by stating
that I am just an amateur.

I hate throwing things out. And, I hate spending money on parts that cost
more than the instrument. So, if I had an HP 410 that had a bad probe and I
did not wish to invest in a new tube, I would find a tube that would fit
into the probe and used the appropriate filament voltage. Even a triode can
be used as a diode. The fact that the fitting of the tube might destroy the
frequency response may not be a big factor. Heck, we usually only operate
up to 450 MHz. Even if the calibration is not absolutely correct, it can be
tested easily with a signal generator and calibrated with a calibration
chart. What you end up is a ******* HP 410, which is still better than a
broken one.

I must admit that I have *******ized a lot of things instead of throwing
them out. Some of the stuff I have works better than when it left the
factory. Some does not. In each case, I have outsmarted the trash man.

73, Colin K7FM

COLIN LAMB wrote:
"Messed up probes are the #1 reason than many otherwise good 410Bs get
junked, which is a shame."

My response might offend the purists, but I can defend myself by stating
that I am just an amateur.

I hate throwing things out. And, I hate spending money on parts that cost
more than the instrument. So, if I had an HP 410 that had a bad probe and I
did not wish to invest in a new tube, I would find a tube that would fit
into the probe and used the appropriate filament voltage. Even a triode can
be used as a diode. The fact that the fitting of the tube might destroy the
frequency response may not be a big factor. Heck, we usually only operate
up to 450 MHz. Even if the calibration is not absolutely correct, it can be
tested easily with a signal generator and calibrated with a calibration
chart. What you end up is a ******* HP 410, which is still better than a
broken one.

I must admit that I have *******ized a lot of things instead of throwing
them out. Some of the stuff I have works better than when it left the
factory. Some does not. In each case, I have outsmarted the trash man.

73, Colin K7FM


Have a look at Tubeworld

http://www.tubeworld.com at

They advertise NOS EA53 for $10 each

73 Lionel VK4NS

It appears they have zero in stock.

Barry - N4BUQ