21fbp22 red gun advice

[Electronic M]

Timmy, a booster or isolation type booster only act on the filament wires of a CRT by inserting a transformer in between the heater supply of the set and the heater of the CRT. All other wires of the socket are merely jumpered from the male to the female connector of the booster. A regular booster just steps up the voltage to the heater which increases cathode emissions due to the increased heat boiling off more electrons from the cathode. An isolation transformer is used to eliminate the DC path between the heater supply of the TV and the CRT heater to cure the symptoms caused by a heater to cathode short inside the tube. An isolation booster merely combines the functions the booster with that of the isolation transformer.
All roundy color tubes(and all color and monochrome CRTs that I know of) have only two filament pins.
Given this and the fact that there is only one filament circuit loop through the socket(meaning that the filaments for all three guns have to be wired together in series or parallel for all of them to light) there is no way for a booster, isolation type or not, to act on only one gun in a color tube.

What you describe is impossible unless it operates on vastly different principles from the vast majority of, if not all other boosters made.

You are either remembering wrong or you posses an extreme rarity that many folks here(myself included) would very much like to know the operational principles of.

I'd like to see a picture of this device as well.

[rca2000]

Well, I DO remember. My recent hospital stint did NOT in ANY way damage my memory.

NOt sure if I have seen one myself, but I* THINK I have. I KNOW I have read about them. They seem to be a small, rectangular device, that connects to the CRT in some way to boost the emissions and NOT just raising the filamant voltage. i know They were advertised in radio--electronics. Jack Darr reviewed one, and talked about how good one did for a tube with a weak red gun. The device had a control on it that would adjust to how much "boost" was needed for the bad gun.

[rca2000]

Seems that I remember reading they were made by someone like "Oneidea", or something like that.

[mstaton]

Originally Posted by Electronic M

An isolation transformer is used to eliminate the DC path between the heater supply of the TV and the CRT heater to cure the symptoms caused by a heater to cathode short inside the tube.



I'd like to see a picture of this device as well.

I think you mean AC path. there are no DC filament voltages

[old_coot88]

Originally Posted by mstaton

I think you mean AC path. there are no DC filament voltages

By "DC path", he means the fault condition that occurs when there's a heater-cathode short. When this happens, it kills all luma (B&W signal) displayed by the CRT, while leaving the chroma display unaffected. Rapping on the neck of the CRT will usually reveal the condition, causing the luma to flash in intermittently.

An isolation booster will eliminate the "DC path" but introduces a new problem: the parasitic capacitance between the secondary and primary windings of the isolation xfmr. causes smearing-out of fine detail in the pic.