CurtPalme.com Home Theater Forum

front_range · Posted: Sat Apr 05, 2008 6:13 pm Post subject: T180 tube in a Barco 708

I'm trying to get a Barco 708 working that has had some HV arcing, and since I didn't have any spare HV leads handy, I just decided to put a worn T180 blue tube with a good anode lead in place of the blue P16NLG with it's suspect lead. To my surprise, the T180 tube produced a bright raster, which is the first time I've seen this set light up at all. I thought the T180 and P16 were interchangable? I know the 708 has used both at one time or another, and the neck boards are identical regardless of which CRT is installed. No amount of adjustment of G2 affects the visible raster???

Nitmoe · Joined: 10 Jan 2008 Posts: 60 Location: Iowa, USA

I am not familiar with this PJ, but I do know that sometimes when sets are available with multiple tube types, a very simple mod must be done. Even though nothing else in the set is different, the tube may require a different voltage. for example, the Electrohome ECP's could have a sd-187 or a 07MS tube installed, but voltage is different. Look at this link, see the photo, look at the bottom right corner. You may need to make some type of similar mod to use the T180 tubes.

http://www.curtpalme.com/ElectrohomeECP_Layout3.shtm

front_range · Posted: Sun Apr 06, 2008 12:57 pm Post subject:

Yeah, I know I'd expect to see a minor mod between the two tube types except the part numbers for the shift & focus board as well as the neck boards are the same for the sets whether they came with T180 as in the 701s, or the P16 as in the 708. And Barco seems to change the part number on any board change - no matter how subtle. Anyway, its not a big deal, I had spare P16's with good anode leads, I just didn't want to put a new good tube in the set till I had everything else running. I guess it will remain a mystery.

**Curt Palme** · Posted: Sun Apr 06, 2008 2:40 pm Post subject:

Charlie at VDC told me that the P16s will drop right into the 180 chassis, but doing the reverse will overheat the cathode, and the T180 will die quickly.

I'd think the changes are in the neckboard.

front_range · Posted: Sun Apr 06, 2008 3:01 pm Post subject:

Ooops, my bad. I had cross referenced them as being the same, but I just actually compared the two and there is a difference between them. It looks like the 701s used a R762559 w/ another label 1096313 neck board and the 708 used a R762559 with a label 1140689.