Which one ? Tek 465B or HP 1740A ?

[BravoV]

Got an offer locally for two old scopes, both 100 Mhz and in good physical condition, but can only do brief power up test and thats it, no further detail testing allowed, yeah, sound strange, cause the place that is selling these is more like flea market and its kinda gambling I know. 

Ideally I should grab both  , but unfortunately I can only afford one. 

Maybe my question is more on how easy to fix them, also spare parts replacement/availability and other possible issues that I should aware of ?


Also there is other offering for a 350 Mhz Tek 485 but much more expensive that these two, any suggestions on this particular one ?

[vk6zgo]

I would go with theTektronix,as I've always thought they did a better job with Oscilloscopes.

If you were comparing Spectrum Analysers,I'd go with HP.

But that's just me.

VK6ZGO

[w2aew]

Both are good scope - but I'd definitely go with the 465B.  It was by far the largest selling scope of it's class in its day.  There are a LOT of them out there, and therefore a lot of parts and expertise in the event that you may need to repair it.  I don't think you can say that about the HP unit.

The 485 is also a gem - 350MHz and a really nice razor sharp CRT.  However, the screen size is a little smaller than the 465B.  If you really don't need the extra bandwidth, then the 465B would probably be the best unit for you.

[Conrad Hoffman]

The 465B was a great scope, IMO far better than the HP stuff. Remember though that this is a very elderly scope by now, and you can expect stiff controls, dirty controls, cracked plastic couplers and related molded parts. Caps can be going bad, though they did use good parts. The packaging density is very high for its time, so working on it can be difficult. It's a complicated scope in terms of circuitry. It's surprisingly heavy. If it's all that's easily available, I'd go for it, just don't pay too much and go in with your eyes open as to the potential for problems.

[FreeThinker]

I had a Tek 465b, travelled 1000's of miles in the back of my car and never missed a beat. Never had an HP but can testify to Tek's robustness.

[rf-loop]

I have never own or handle Tek465B but several 465.
465 and (465B somewhat better  but this I have only know from my some friends) have been good scopes as long as someone have repaired these without knowledge how to do.  (same for HP scopes).

I have some HP1741A. After long time I just take one random unit to table and take picture. It works always robust, where ever it have been or transported. (This one is ex military)

This is 1741A but well same as 1740 exept analog memory.

In picture is one random around 20ns pulse in memory and cable disconnected so that everyona know picture is stored.

I take picture with very bad light and all camera settings bad, just snap shot becouse busy. Trace is lot of better in nature and if trace is not stored it is more sharp. (specially if switch scope to conventional (storage totally shutted down) mode (this special switch is back side). I have never seen better focus in any tektronix scope, around same in some models but not better.

If 1740 or 1741 is in good condition it is really good oscilloscope.
Also if need service.. construction is really clever. 

I have repaired and have experience of Tek many types including 7000 series.
HP is more rare but amazing good. (but HP these knobs are easy fragile.. it is weak point. But if knobs are really original condition and in normal use it is not any problem.)

In old times born this legend that there is only one oscilloscope.. Tektronix. It was really true in beginning of "trigged" oscilloscopes and it have nice piece of history how this happend.

Good HP scopes are rare. But Good Tektronix, they can find all places.

But if someone really know what is better in Tek465 than HP1740-1 I'm interesting becouse after long experience with this kind of oscilloscopes I do not really know.

(maybe tektronix delayed sweep is littlebit more nice... but one like berries one like apples.)

[tekfan]

Don't forget the HP1740 has 1mV/div sensitivity (although the bandwidth drops to 40MHz in that position). It still beats the Tek that just has 5mV/div sensitivity. The HP goes up to 20V/div so you don't even have to use a probe if looking at relatively high voltage low frequency signals. It also has built in 50 ohm terminators which are very handy if you don't have an external feed through termination.

The delayed time base is of a slightly older design. It's exactly the same operation as the Tek 465 (without B).The Tek 465B model has a slightly more advanced delayed time base but you will rarely use it unless you want to look at very complex analog signals, video...

The HP scope also has a trig view button which essentially brings up a third trace so you can see exactly what the scope is triggering on. The Tek has something similar but can't display it as a third trace on the screen.

The Tek has a nice feature (if used with Tek probes). There are two lights behind the volts/div knobs that light up according to what probe you have connected. Either a 1X probe (or no probe) or a 10X probe.

All in all both are very nice scopes. The Tek 465B model was introduced later so you probably don't have to worry about broken shaft couplers. If the knob turns and stops in the extreme positions then you're alright.

[vk6zgo]

As I said,it is just me! Of course,I don't have either of these--I have a Tek 7613.
Huge,yes(though not compared to a 545),but does the job well.

Another very good,but fairly uncommon 'scope is the Iwatsu from the mid '90s--I'd love to find one of those cheap!

VK6ZGO

[amspire]

I have been using the HP1740A as my analog scope, and I have found it great. The trigger view makes it almost a 3 channel scope - it is very useful.

It just works. Great sensitivity. Great trigger. Delayed timebase on my scope is very accurate.

I have used some HP scopes in the past with some odd and not very functional design choices, but this is not one of them.

The Tek scope is one or the great scopes, so I think get the one that looks like it is in the best condition.

Richard.

[lowimpedance]

Both are nice cro's from their time and still good today if in good order. (not been abused).
If you can turn them on you will get a good idea of the life left in the 'tube' as well as any other obvious problems,
like dirty switches. etc. (Take a resistor with you to poke into the vertical inputs to check for deflection when you touch the resistor leg, if they don't have any probes that is.).
Having just played with a 1740a and 1741a, apart from some resistors going high the main area requiring attention is the timebase switches
which thankfully these are very easy to get out and pull apart for a good cleaning with IPA then a light re greasing with the appropriate grease.
The vertical attenuator on the 1740a was also a bit dodgy with some positions even after cleaning the pcb/switch contacts, (Uses gold fingers in a cam driven assembly to mate with gold plated traces on PCB.).
General ease of maintenance with the hp layout is a big plus. It does use a number of custom ic's and hybrids but also a lot of easily found or equivalent parts too,
cannot recall how many the TEK has but I think it uses sockets on just about all semi's including the transistors (someone can correct me on this!).

Shame you can't snag both. I suspect you will find more 465b's though if you NEED spares in the future.

Good luck in your choice
cheers
john

[BravoV]

Looks like 465b wins the vote here, thanks for the tips, definitely will check thoroughly those front panel knobs or switches.

..<snip>..
Shame you can't snag both.

Psstt.. actually I can afford it financially, its just I don't want to trip the alarm at wifey that the compulsive hoarding is back again. LOL

[deephaven]

As I said,it is just me! Of course,I don't have either of these--I have a Tek 7613.
Huge,yes(though not compared to a 545),but does the job well.

Another very good,but fairly uncommon 'scope is the Iwatsu from the mid '90s--I'd love to find one of those cheap!

VK6ZGO

I'm a big fan of Iwatsu scopes too - I have 3 of them!