Sencore CR31A or B&K 470?

I have an opportunity on a couple of CRT testers and thought I'd get some input...For $45 I can get either a Sencore CR31A or a B&K 470. Both are in really good physical shape, the CR31A a little more so. Both are un-tested, but each has a maunaul. The CR31A has a red probe with it too, which I think is for high voltage.

I know a CR70 is the best, but I don't want to invest that much money right now. I basically want to be able to test CRTs, and maybe try to rejuv one if all else seems hopless.

Are these worth it and is one better than the other?

[radiotvnut]

I'd go for the 470. Both are nice models; but, I think the Sencore is old enough to still use "atomic blast" rejuvenation and it may not be able to check newer tubes. Of course, if you don't plan to rejuvenate tubes or check newer tubes; then, it should serve you well.

I've been using a B&K 470 for close to 20 years and it will test most any tube, except the early electrostatic deflection B&W tubes, made from the early days of post-war TV until the end of the CRT era. The rejuvenate function is also fairly easy on CRT's and I've saved more CRT's that I care to try and remember with my B&K.

I think the Sencore has an HV probe and may have some other features; so, you might do good to get both of them, if you can get them for the right price.

[zeno]

It may boil down to what adapters come with it. Also
how old the set-up book is. You can make your own
universal adapter. Will work on any jug except the spring
contact types such as some RCA & Zenith tubes
(which were used in many brands). I had both the CR70 & 470
at the shop & I think they preformed about the same.
The Sencore did go through cables ever few years.
The HV probe is no big deal. They are useless now unless
you do MWO & its not needed for that. Should be able to
get one fairly cheep.

73 Zeno

[Findm-Keepm]

Originally Posted by radiotvnut

I'd go for the 470. Both are nice models; but, I think the Sencore is old enough to still use "atomic blast" rejuvenation and it may not be able to check newer tubes. Of course, if you don't plan to rejuvenate tubes or check newer tubes; then, it should serve you well.

I've been using a B&K 470 for close to 20 years and it will test most any tube, except the early electrostatic deflection B&W tubes, made from the early days of post-war TV until the end of the CRT era. The rejuvenate function is also fairly easy on CRT's and I've saved more CRT's that I care to try and remember with my B&K.

I think the Sencore has an HV probe and may have some other features; so, you might do good to get both of them, if you can get them for the right price.

Ditto, except I've had my 470 for 13 years. Moneymaker back in the day - fixed a few sets to find a soft tube - Clean/Balance made things better. I'd go for the 470, and pick up some molex connectors to make your own adapters along the way. Not too hard - the manual has the universal adapter instructions, and with just about any socket combination, you simply build your own adapters. Neck boards were always a commodity in our shop - save the socket to make an adapter or two!

Also, pick up a piano hinge along the way to replace the plastic hinge that breaks. Use the shortest screws possible, and you can even replace the plastic latch with Velcro. Love mine, but it is ugly!

Cheers,

[zenith2134]

The B&K model 465 tester is the earlier one where the red button for rejuvenation released a bank of capacitance through the CRT neck. Still not sure how much the hi- and lo- settings varied, however.
For checking my '74 Sylvania metal cab color with the black matrix tube it came in handy. Adapters for color on a 470 must have been extensive.

[radiotvnut]

The 465 dates from the late '60's-early '70's and was the first CRT tester I ever owned; however, it uses "atomic blast" rejuvenation and did not have sockets for testing later CRT's. At one point, there was an adapter box (SP65) that would allow the later CRT adapters for the newer testers to be used on the 465; but, I've never seen one of these adapters in person.

During the '60's and early '70's, there were only a small number of CRT sockets. Starting in the mid '70's, more inline gun CRT's started coming out and there were many different CRT sockets. I think the later B&K's had something like 70 socket adapters available (a good many of them being for projection TV's).

[davet753]

I would highly recommend the 470. Out of all the ones I have used, the 470 is far and away the best one.

I used to have a 465, too. While the 465 is definitely an old war horse, you can make your own adapter to use it with the newer CRT's (in case the 470 isn't strong enough to knock it out).

Well, I bought both. I don't know why I need both, but I've got them. I've only played with them just a little so far. The 470 only came with six adaptors, but the CR31A has 21 all together. Neither one had a universal one with it, so I might have to make some.

The CR31 has an issue with setting the filament voltage. When I put the initial setting on say 6v and the fine knob is in the middle it goes to 7v like you'd expect, but turning it only goes about .2v either way. I can't get it down to 6.3v. Anyone know the trouble? Do you guys recommend replacing the caps on these before using them?