16WP4A ion trap?

[N2IXK]

Working on a Philco 51-T1634 with a 16WP4A CRT. The set came to me after having been played around with (several tubes in wrong sockets, etc). It came with a single magnet ion trap, and it makes a good image with it (trap location is about as close to the tube base as possible). Looking at the datasheet for the CRT, it calls for a "dual field" ion trap, not a single.

Is running the tube with the single magnet trap going to cause an issue with ion burn? Can anyone recommend a source for a dual magnet ion trap, or have an extra they are willing to sell?

[dieseljeep]

Originally Posted by N2IXK

Working on a Philco 51-T1634 with a 16WP4A CRT. The set came to me after having been played around with (several tubes in wrong sockets, etc). It came with a single magnet ion trap, and it makes a good image with it (trap location is about as close to the tube base as possible). Looking at the datasheet for the CRT, it calls for a "dual field" ion trap, not a single.

Is running the tube with the single magnet trap going to cause an issue with ion burn? Can anyone recommend a source for a dual magnet ion trap, or have an extra they are willing to sell?

All the 16WP4's I seen used a single magnet ion trap.
Even the Philco made 12LP4 used a single magnet ion trap. When I put the tube in storage, I put the trap on to prove it's the proper one.

[N2IXK]

Looked up the original Philco (Lansdale Tube Company) datasheet, and they just call for an "ion trap" and makes reference to a "#108 Ion Trap".

The reference to the "dual field" trap came from an RCA datasheet for their 16WP4A. Perhaps they used a different gun design than Philco did?

Definitely works well with the trap that came with the set, but the "sweet spot" for the location puts it right up against the CRT base.

[John Marinello]

"Beam bender" is the better term over "ion trap". The angled gun aims both the electrons & ions away from the screen. The beam bender redirects the electrons to the center of the screen, and has little effect on the heavier ion. If you have a decent image, you have the correct magnet. Earlier tubes used "double field" magnets. As they were rebuilt, all or most went to single field magnets.

[Eric H]

Flip the trap front to back and see if the neck position gets better. You might also have to rotate it 180 degrees after flipping.

[Yamamaya42]

Originally Posted by dieseljeep

All the 16WP4's I seen used a single magnet ion trap.
Even the Philco made 12LP4 used a single magnet ion trap. When I put the tube in storage, I put the trap on to prove it's the proper one.

that Philco must be a unique version, cause my RCA 12LP4 and this listing for sylvania uses a dual trap.
:O
https://frank.pocnet.net/sheets/168/1/12LP4.pdf

[dieseljeep]

Originally Posted by Yamamaya42

that Philco must be a unique version, cause my RCA 12LP4 and this listing for sylvania uses a dual trap.
:O
https://frank.pocnet.net/sheets/168/1/12LP4.pdf

Philco made their own jugs! The EIA number on the base is 260. It's also an original tube that came with the set when new.

[Yamamaya42]

Originally Posted by dieseljeep

Philco made their own jugs! The EIA number on the base is 260. It's also an original tube that came with the set when new.

Their sets always were a bit weird!