Tektronics Scopes


Alan Young <agyoung@...>
 

Hello All,
I am in a situation where I have been physically disabled. I am an amateur radio operator and am looking for a scope for general purposes. My partiality runs towards a 465 as that is what I used in the Coast Guard in the mid 70's. It was state of the art and I always thought that we somehow lucked out to get them. Most of our scopes were Dumont or Fairchild surplus from the Navy. We almost never got new test equipment. I am looking for a scope just to play with associated with hf stuff 50 MHz and below. I see a lot of 465's on Ebay and would love to have one just for nostalgia. I have put a bid in on a 2246 which was rather low so I doubt that will happen.
I guess my question is would the 465 be a better bet than something like a 2246 for tinkering? I do notice that the electrolytic power supply caps seem to be a problem with the switching power supply on the 22xx series and I'm not sure I can physically replace then if needed.
Again, my use for a scope is tinkering. The 465 for nostalgia.
Any thoughts or help would be most appreciated.

There is a tremendous wealth of information on this site and I can read posts for hours!

Thanks,

Alan Young
N5AGY


 

Hi Alan,

The 2246 is quite a nice scope, but a big change from a 465, and maybe more than you need for the kind of work you want to do. In the 2200 series there are some very nice, lower priced scopes that will probably meet your needs; I would consider a 2215/2215A or 2235/2235A as common, full-featured scopes.

The advantage of the 2215 and 2235 is that they are easy to work on and do not require much, if any, unobtainable parts to repair their most common failure modes. The 465, from the decade before the 2200-series, has more parts that are no longer obtainable, can only be obtained at significant cost, or must be salvaged from another scope. That is not say anything bad about the 465: it's a beautiful instrument, easy and fun to use, and built like a tank (both in durability and mass). The 2200-series were a cost-cutting effort by Tek in the 80s to compete with new foreign competition, and they feel like it. The 2200-series are still very good scopes, but they feel more flimsy (on the up-side, they are much lighter than a 465, which may be a concern for you, depending on your disability).

The features of a 2215 or 2235 are very similar to the 465, right down to having very similar controls for most functions. The 2246, being a much later entrant in the 2200-series (and actually looking a lot more like a 2400-series scope) has significantly different controls than the earlier scopes, so it will feel very different when you use it (it will also have features that the earlier 2200-series, and the 465 lack, like cursors, on-screen readout, and automatic measurements, so it's a trade off).

Any scope of this age, both 70s era 465s and 80s era 2200-series scopes are going to have dried out electrolytic capacitors. The problem gets a little worse with newer old scopes (late 80s/early 90s vintage) that have particularly destructive surface mount caps. The 2246 is right on the boundary for those specific bad caps, and the pictures I see of the insides on TekWiki don't seems to show any of them, so maybe that's not an issue for this model. Certainly the 2215/2215A or 2235/2235A do not have the bad surface mount caps.

That said, yes the switching power supplies have some specific failure modes that can apparently be challenging to diagnose, but the easy of servicing the 2200-series makes up for some of that, I think. I have worked on both the 475, which is almost identical to the 465, and a number of 2200-series scopes, and the 2200-series are arranged so that you can much more easily access both sides of the PCBs, even in the power supply section, while the 475 (and 465) can require significant disassembly to get to the power supply boards. Also, since the 2200-series are much lighter than the 400-series it is easier to move it around when working on or with a 2200-series scope (the 2215 weighs about 13 lbs, while the 465 weighs about 23 lbs).

Just my 2-cents.

-- Jeff Dutky


-
 

Alan,

If you are unwilling or unable to repair a scope then my first advice
would be that when it comes to E-bay, don't buy anything that isn't
classified as "New" or "Used". Under E-bay's rules, anything sold in those
categories must work, regardless of any disclaimer that the seller puts in
their description. If the item arrives and doesn't work or is damaged or
not as described, then per E-bay and PayPal's rules, you are entitled to
all of your purchase price back and any shipping and/or packing fees that
you paid. And the seller must pay for the return shipping if he wants the
item back. It's a pretty iron clad guarantee and E-bay and PayPal WILL
enforce it, but only as long as you buy an item that is "New" or "Used". It
helps to keep records and photos of everything. If I get a package that
looks beat up, I take pictures of it before I open it and more pictures as
I open the box and before I remove item, then more pictues as I take the
item out and then of the empty box and the packing material that was in it
and then all sides of the item. And more picture of the inside if I open
the item up. I bought a complete original BC-348 radio from E-bay a few
years ago and it was packed unbelievably poorly and smashed when I got it.
And I had very specifically asked the seller to pack it *well* and offered
to pay extra for that but he didn't do it. He just crammed it in an
undesize thinwall box with a single sheet bubble wrap. He and I went round
and round about it but I finally filed a claim with E-bay, sent them the
pictures and they *immidiately* refunded my money and paid me to ship the
item back to the seller. By the time that it was over with, the seller not
only didn't make a penny on the sale, he also paid almost $180 for the
shipping!

For tube type equiptment, you really shoud try to avoid shipping and
try to find something locally that you can go pickup in person. For big,
heavy or delicate items, when I search E-bay one of the things that I like
to do is to sort the results by distance from me. If I find something
nearby I then contact the seller and make sure that they allow local pickup
before I buy. I've bought dozens of big heavy items such as linear power
supplies and this has wrorked out well for me.

Post up your location and someone here might be able to help you out.

Joe

On Tue, Apr 27, 2021 at 1:39 AM Alan Young <agyoung@cox.net> wrote:

Hello All,
I am in a situation where I have been physically disabled. I am an
amateur radio operator and am looking for a scope for general purposes. My
partiality runs towards a 465 as that is what I used in the Coast Guard in
the mid 70's. It was state of the art and I always thought that we somehow
lucked out to get them. Most of our scopes were Dumont or Fairchild
surplus from the Navy. We almost never got new test equipment. I am
looking for a scope just to play with associated with hf stuff 50 MHz and
below. I see a lot of 465's on Ebay and would love to have one just for
nostalgia. I have put a bid in on a 2246 which was rather low so I doubt
that will happen.
I guess my question is would the 465 be a better bet than something like a
2246 for tinkering? I do notice that the electrolytic power supply caps
seem to be a problem with the switching power supply on the 22xx series and
I'm not sure I can physically replace then if needed.
Again, my use for a scope is tinkering. The 465 for nostalgia.
Any thoughts or help would be most appreciated.

There is a tremendous wealth of information on this site and I can read
posts for hours!

Thanks,

Alan Young
N5AGY






Alex
 

On Mon, Apr 26, 2021 at 10:39 PM, Alan Young wrote:

I have put a bid in on a 2246
which was rather low so I doubt that will happen.
If you will be considering one of the 224x line of scopes (2245/2245A, 2246/2246A, 2247A, and 2252A), I'd aim for the 2247A model, it has a couple of very useful additional counter/timer features over the 2246 like direct frequency/period readout which might be handy for amateur radio work, and this model should in most cases command a very similar price as the 2246/A. Or at the very least try to the the improved A version 2246. The next option would be the 2252A which is one up from the 2247A and the only difference is that the 52 has one additional blue button on the front panel labeled "Hard Copy" that allows to print the screen. But in all other respects the 2252A is exactly the same as the 2247A, although it does not come up for sale as often. I have owned a 2247A for 10 years now, and even though I have other scopes including a spec-wise much superior 2465B, the one that almost always gets fired up first is the 2247A as it is a very intuitive scope that has tons of nice and easy to use features. The only thing I had to do to it so far was to preemptively replace all the fast rectifier diodes as it is recommended, and twice the internal Lithium battery (the one that originally came with the scope was already dead). This scope also does not store any cal constants in volatile memory so the demise of the battery does absolutely not affect calibration.

All in all I'd say the 2247A is a nice middle ground between the lower cost design 22xx line and the higher tier 2465/67. Yes the 224x scopes power supply requites a bit of disassembly but nothing as complicated as the 2465. Even the 22xx line requires some disassembly to get to the power supply by removing the shielding cage and the bottom plastic cover, which sometimes can be a bear to remove, so no free lunch on any of these scopes in terms of working on recapping or repairing the power supply which is a given on scopes of this age unless the previous owner has gone fairly recently through the process.