Why don't I see - compact B&W portables?

[peverett]

The two portable RCAs that I have with power transformers are both 19" sets with three IF stages. I believe that one of the chassis numbers is KCS149. They use the 7 pin tubes, such as the 6BZ6. These are from the early to mid 1960s with the 110 degree CRTs. Both of them have worked well until recently-one has developed a horizontal sync issue. I also have two series string "Sportabout" TVs from RCA. These also have three IF stages.

The only RCA that I have with two IF stages is a KCS146 chassis set with 16 inch CRT. It works also, but has a very worn out and touchy volume control. In addition, I had to replace the vertical linearity control with a fixed resistor, the orignal was fried.

The Seventeeners(I have some of these also) have 3 if stages, but the horizontal output and damper are on the PC board, not a good idea. At least in the case of these sets(unlike later Philco sets), deep sockets were used that kept most of the heat away.

I also have never seen Zenith sets with two IF stages. Even the 12 inch B&W set that I have contains 3 if stages(and the handcrafted chassis).