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-   -   Pilot tv resistor for crt (http://www.videokarma.org/showthread.php?t=267211)

timmy 06-15-2016 04:51 PM

Pilot tv resistor for crt
 
I'm thinking of putting a separate filiment transformer for the crt in my pilot. What I would like to find out is what ohm and watt resistor to put in place of the crt filiment, the best that would mimic the crt so as it don't affect anything in the heater string.

jr_tech 06-15-2016 05:28 PM

3KP4 data sheet here:

https://frank.pocnet.net/sheets/049/3/3KP1.pdf

The first two lines of data are the heater parameters... An ohms law calculation will give you the answer.

jr

bigaudioal 06-16-2016 03:32 PM

Easier way to go would be to place a bi-directional TVS diode across the CRT filament. Done.

I used this one:

Diode part no. P6KE8.2CA-TP. Got it here:

https://www.arrow.com/en/products/p6...ponents#page-1

Just follow the wires from pins 1 and 11 of the CRT (Heater). Wherever they connect in the set, put the diode across those two tube pins. Protects the CRT from the start up surge and no separate transformer needed and no need to compensate for the missing CRT heater in the rest of the string. If I remember correctly, I had to extend the leads off the diode, but installation took about 5 minutes.

timmy 06-16-2016 03:48 PM

Quote:

Originally Posted by bigaudioal (Post 3164725)
Easier way to go would be to place a bi-directional TVS diode across the CRT filament. Done.

I used this one:

Diode part no. P6KE8.2CA-TP. Got it here:

https://www.arrow.com/en/products/p6...ponents#page-1

Well I have the diodes coming part number, 1.5ke8.2ca I think they clamp at around 7 volts. The only reason I was looking for the resistor for the filiment is because I have a spare 3 inch crt for my pilot and this tube has the cathode shared with the heater so if I use a 6.3 v transformer I could use that tube or any other. Plus I will be putting the diode in as well.

bigaudioal 06-16-2016 03:53 PM

Quote:

Originally Posted by timmy (Post 3164726)
Well I have the diodes coming part number, 1.5ke8.2ca I think they clamp at around 7 volts. The only reason I was looking for the resistor for the filiment is because I have a spare 3 inch crt for my pilot and this tube has the cathode shared with the heater so if I use a 6.3 v transformer I could use that tube or any other. Plus I will be putting the diode in as well.

I got ya. My pilot came with a good 3KP4 that puts out a great pic. I was very fortunate. Diode does a good job of protecting from the start up surge. It is visible noticeable. CRT filament does not get extremely bright and then die down to normal anymore. :thmbsp:

Findm-Keepm 06-17-2016 11:05 AM

I've used the P6KE7.5CA - keeps it real safe at 7.5V, and a buck gets you 10!

My Silvertone 21" consolette and Emerson luggable are still going strong with them.

Cheers,

timmy 06-17-2016 11:33 AM

Hey findm keepmm is that SAMs you have the 95-6 is that the 208tr does it show a ballast or 6x5 . Could you tell me what value Micas are shown in the verticle section of your 95-6 SAMs .


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