Just to wrap this up.... Since I have been only having marginal success with the cap/resistor NiCd substitute, I have decided on my alternative. My plan is to cut some aluminum blanks the same size as

Success. After using the bench supply, and giving the unit a couple of minutes to warm up, I started rotating the intensity control. As I swept to the upper end, I could see evidence of a trace, altho

Make that horizontal sweep set way too slow. (Not trace :-) - Mark N1VQW

Thinking I might find a use for a 1502 parts unit, I picked one up. Although it was "parts only" I decided to see what kind of shape it was in. NiCd batteries shot, and starting to leak a bit. So I tr

Hi Tom. Got around to testing the 1502 using a bench supply. As you suggested, when hooked up, the 1502 power supply started operating as expected. All the voltages appeared to be to spec. Although st

Very true. However, my own problem with NiCd batteries is I use the equipment so infrequently I would be constantly replacing batteries. I understand this is less of an issue with NiMH and Lithium bat

Hi Tom. I have a 2200uF cap, per the TekWiki. Works fine for the 1503, so I expect there is something else going on in the 1502. That's why I'm still scratching my head. I really need to find some (of

Hi Dave. I checked the three caps, and C6415 is open. The other two read good on my cap/ESR meter (about 400uF and ESR both < .5ohm). I'll definitely replace the open one, and may do the other two as

Good to know all this information about the batter charging circuit. One thing I do have going for me is the same modified "battery pack" I'm using to troubleshoot my 1502 works fine in my 1503. (I pr

Good to know. I did not. I just checked, and when powered on, the battery meter reads about 1/16" past/above the upper portion of the green area. I'm not sure if this matches what you mean by "excessi

Hi Tom. I haven't tried supplying power directly to the banana plugs, but the parallel cap/resistor battery substitute (ala TekWiki) seems to work fine, as the battery meter on the front panel indicat

I've had a 1502 project for a while, and I'm finally getting some time to work on it. I've already done the cap/resistor battery "mod" as suggested on the TekWiki, and I have 14.4 volts on the "BATT"

Hi Walter. I got my set from Qservice. Very good copies. - Mark N1VQW

Hi Dave. Might it just be easier to drill out the rivetnut and replace it completely? Since you are drilling out the screw anyway.) Especially if they are the aluminum ones instead of the steel ones.

Hi George. While 4x40 is a very common size now, I have some "older" Tektronix scopes (I believe they are the 200 series) where the set/grub screw is indeed 5x40. Just another data point :-) I'll seco

Brad, the schematics and other information were in pert 2 of the article. It appeared in the May 1970 issue (starting on page 39). The archive has that issue as well (...1970-05.pdf). - Mark N1VQW

Several :-) I have one of the MS-15 scopes mentioned by Dennis; there was also a dual channel MS-215. I also have some 222 and 224 scopes. I do have them operating on batteries (using the Gates SLA ce

This could be very useful. It appears as though the circuitry can be modified to handle Lithium batteries. Although I took the approach of just trimming some plastic and wiring up 4 Cyclon 0810-004 ("

I don't know :-) That's why I'm sticking with the (at least for me) readily available Cyclon SLA batteries. Maybe someone else is more versed in battery maintenance and could answer. - Mark

Just to follow up on this a bit. Most "good" references I have been able to find say it isn't really safe or good for long battery life to use an SLA charger on Lithium batteries. (With the exception