Convert low impedence to high simply by adding a resistor across the terminals?

[Pac-Fan]

I just picked up a few tubes in a bulk buy. Some had chassis, most did not.

Most of the time, replacement TV tubes I find are newer 15 ohm vertical, too high for use in K4600 chassis (that expect 8 and have large pincusion problems with 15's) and is way too low for use in G07's or K4900's which require 45 to 55 ohm vertical.

One of the tubes I picked up had a resistor soldered between the terminals on the yoke for vertical. The vertical resistance measured 55 ohms, perfect for a G07.  However, I'm concerned that this is caused by the parallel resistor in place and not the true yoke resistance. 

Admittedly, I haven't had time to look up the color band codes or desoldered the resistor to check what it's rated as, I will do so later this evening.

I'm curious if this is safe to "test" in a G07 or if I will cause damage to the chassis?  All other specs (same pinout, same horizontal resistance) match as well.  Also, it's interesting that it is wired in parallel to the windings rather than in series.

Is this a simple way to make low impedence yokes work as high impedence chassis, or was this a specific yoke for a specific chassis that wouldn't (safely) work on a G07?   There were no common chassis with this lot for the ones that did have them, just oddball ones, so I have no idea what this tube mated with originally.

[Rickn]

No nad then again no.

In other words no the addition o a resistor does not change the impedance properly.

Imepedance is a combination of Resistance, Inductance and Capacitance. The latter is not involved with yoke imedance.

The most important factor is Inductance-- much more than resistance.

Those that suggest resistance are only doing so because most people have an ohm meter.

A professional knows better...

Any way second no is that it is not likely to fix your matching of the tube.

As far as pincushion problems, not necessarily impedance. The original G07 had a non-pinfree tube.

After that came "Pinfree Tubes" where as Pincushion correction was done by the yoke and required no pincushion circuit.

The quickest way to tell is to look at the yoke. If there is 4 metal "wings" mounted to the circumfrence of the yoke it is pin free.

If just plastic, then non-pinfree.

There are other issues caused by impedance mismatches, depending on how drastic they may be be overcome by chassis mod's

Good Luck

Rick Nieman
Rick@niemandisplays.com