83 tube in Hickok tester

Discussion:

(too old to reply)

Bigfoot048

2011-11-01 16:10:13 UTC

Is there any reason why they use an 83 rectifier tube in a Hickok tube
tester instead of a 5Z3? Would a 5Z3 be satisfactory or should I stick
with an 83?

jas

John Robertson

2011-11-01 16:45:46 UTC

Permalink

Post by Bigfoot048
Is there any reason why they use an 83 rectifier tube in a Hickok tube
tester instead of a 5Z3? Would a 5Z3 be satisfactory or should I stick
with an 83?
jas

The 83 is a mercury vapour low-voltage drop rectifier. I see no reason
why you can't use two 1N4007 diodes (1A @ 1000V) in series for each half
of the rectifier tube (to meet reverse breakdown requirements). You
may need a dropping resistor if you can't adjust the plate voltage low
enough. I would also add a 1/2A fast-blow fuse on each 1N4007 to protect
the transformer in case a diode shorts.

The 5Z3 has a much larger voltage drop and probably would not perform
satisfactorily.

Some specs:

5Z3 - Tube Voltage Drop: 58V @ 225ma DC, Fil. current 3A
83 - Tube Voltage Drop: 15V @ 225ma DC, Fil. current 3A
1N4007 - Forward Voltage Drop: 1V @ rated current or less.

Doesn't anyone have the 1964 GE tube Catalog online?

John :-#)#

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Alan Douglas

2011-11-02 01:40:01 UTC

Permalink

Post by Bigfoot048
Is there any reason why they use an 83 rectifier tube in a Hickok tube
tester instead of a 5Z3? Would a 5Z3 be satisfactory or should I stick
with an 83?

The voltage drop in an 83 remains at 13V over the entire AC cycle. The
drop in a vacuum rectifier such as the 5Z3 varies with plate current,
and is considerably higher. This throws the Gm calibration off.

You can replace the 83 with a pair of silicon diodes (modern 1N4007s
have far more than enough PRV rating). If you wire them directly to
the 83 filament winding center tap on the power transformer, that's
all you need. If you want a plug-in replacement, since the actual
center tap does not appear at the socket, you create an artificial one
with two 10 ohm 1W resistors wired in series across the filament pins.
The rectifier cathodes connect to the mid point of the two resistors.
You need an old tube base to make the adapter.

Calibration may be a little off with the silicon diodes, but I've had
good luck with several different Hickoks.

Alan

DumpsterDiver

2011-11-02 01:22:43 UTC

Permalink

Post by Alan Douglas

Post by Bigfoot048
Is there any reason why they use an 83 rectifier tube in a Hickok tube
tester instead of a 5Z3? Would a 5Z3 be satisfactory or should I stick
with an 83?

The voltage drop in an 83 remains at 13V over the entire AC cycle. The
drop in a vacuum rectifier such as the 5Z3 varies with plate current,
and is considerably higher. This throws the Gm calibration off.
You can replace the 83 with a pair of silicon diodes (modern 1N4007s
have far more than enough PRV rating). If you wire them directly to
the 83 filament winding center tap on the power transformer, that's
all you need. If you want a plug-in replacement, since the actual
center tap does not appear at the socket, you create an artificial one
with two 10 ohm 1W resistors wired in series across the filament pins.
The rectifier cathodes connect to the mid point of the two resistors.
You need an old tube base to make the adapter.
Calibration may be a little off with the silicon diodes, but I've had
good luck with several different Hickoks.
Alan

One problem I have had with this plug-in replacement is the inability
to set the "Line Adjust" to the mark. Looks like maybe a combination
of relatively high line voltage in my area (typ. ~125 V) plus the
significant reduction in power transformer load (3 A, if I recall
correctly) of the #83 filament. Net result is that the meter needle
tends to sit a bit right of the mark even with the pot all the way
CCW. Running the tester through a "Variac" solves the problem (and
also facilitates getting the filament voltages smack on the nominal
values), but that's probably a bit more trouble than most folks are
willing to put up with for the sake of saving $15 or so for a #83
tube.

I'm talking here about the military TV-7 testers which are the only
Hickok-types I've had fairly large experience working on. But I
suspect the 533 and 539 civilian models probably show similar
behaviour.

DD

^^;;^^

Morcegao

Michael A. Terrell

2011-11-02 04:41:11 UTC

Permalink

Post by John Robertson

Post by Bigfoot048
Is there any reason why they use an 83 rectifier tube in a Hickok tube
tester instead of a 5Z3? Would a 5Z3 be satisfactory or should I stick
with an 83?
jas

The 83 is a mercury vapour low-voltage drop rectifier. I see no reason
of the rectifier tube (to meet reverse breakdown requirements).

Why would you want them in series? You could use the 1N4007 and a 13
to 15 V Zener to match the drop of the 83 recitifer in each diode.

Post by John Robertson
Doesn't anyone have the 1964 GE tube Catalog online?

How about RCA tube manuals?

http://www.ebay.com/itm/200644139680 is 21 RCA reciving tube manuals for
$7.99 including shipping.

* RCA R-10 ... 87 Pages
* RCA RC-11 ... 164 Pages
* RCA RC-12 ... 164 Pages
* RCA RC-13 ... 196 Pages
* RCA RC-14 ... 257 pages
* RCA RC-15 ... 260 Pages
* RCA RC-16 ... 324 pages
* RCA RC-17 ... 324 Pages
* RCA RC-18 ... 356 Pages
* RCA RC-19 ... 388 Pages
* RCA RC-20 ... 426 Pages
* RCA RC-21 ... 484 Pages
* RCA RC-22 ... 543 Pages
* RCA RC-23 ... 612 Pages
* RCA RC-24 ... 580 Pages
* RCA RC-25 ... 611 Pages
* RCA RC-26 ... 657 Pages
* RCA RC-27 ... 676 Pages
* RCA RC-28 ... 788 Pages
* RCA RC-29 ... 756 Pages
* RCA RC-30 ... 762 Pages

--
You can't have a sense of humor, if you have no sense.

John Robertson

2011-11-02 17:04:32 UTC