HP 1740A vs Tektronix 465B - Page 1
Forum section: electronics / testgear

author: bd139
author_rank: Super Contributor
timestamp: August 24, 2017, 09:13:12 pm
content: I've owned a couple of 465B's and currently own a 1740A. Is there any technical merit of the 465B over the 1740A (other than the graticule illumination which is crap on the 1740A)?It's my pass time playing with these things rather than a purchase decision here btw.

author: tggzzz
author_rank: Super Contributor
timestamp: August 24, 2017, 09:58:54 pm
content: Quote from: bd139 on August 24, 2017, 09:13:12 pmMuch of a muchness. Personally I like the "graticule illumination" on the 1740a.465: smallerincluding smaller screen1740: 50ohm terminationalbeit without overload protectionIf I had to choose between two working examples, I'd probably choose the 1740a (partly because I could probably and inexplicably flog the 465 for a higher price!).

author: bd139
author_rank: Super Contributor
timestamp: August 24, 2017, 10:44:35 pm
content: Yes that was the fate of my Tektronix kit. It always ended up getting flogged and a sub £20 unit from Philips / Hameg actually ended up doing the work. The difference was spent on beer.I'm using external feed through terminator with the 1740A as I don't much fancy replacing the other one and I'm using it to measure RF power at the moment

author: G0HZU
author_rank: Super Contributor
timestamp: August 24, 2017, 11:08:51 pm
content: I've never liked the 1740 scopes from HP as we had quite a few of them at work in the early 1990s. They simply weren't built solidly enough to withstand daily use in a busy lab where a scope would typically get moved between benches on a daily basis. The company was still very small back then and we didn't have enough scopes for all of the engineers in those days and everyone borrowed what they could when they could. So a scope had to withstand quite a bit of physical stress on a regular basis.Everyone hated these Hp174x scopes because they became so unreliable. The various knobs or buttons would easily break off or the timebase knob would come loose or break and these scopes also suffered a fair few internal failures. The rotary controls often wore out internally through heavy use and the tiny push buttons would often fall off the front panel and go missing.By contrast we had some Iwatsu 5711 scopes that were much better built and the knobs and controls were reliable despite similar usage patterns and these were much more popular. We also had some Philips scopes that were almost as bad as the HP models in terms of reliability and build quality. We didn't have any Tek 465 scopes to compare but at my previous job the Tek 465 was very popular and seemed very reliable.

author: G0HZU
author_rank: Super Contributor
timestamp: August 24, 2017, 11:30:26 pm
content: The 465 has a CH1 output at the rear panel and if you connect a frequency counter here you can use the scope as the front end of the frequency counter via a x10 scope probe. This allows you to 'see' the waveform (on the scope display) as you are probing with the counter. The other bonus is that the CH1 connection at the rear has some voltage gain and this can help boost the sensitivity of the counter. You can also connect a spectrum analyser to the CH1 rear BNC and look at waveforms in the time domain on the scope and also the frequency domain with the analyser. All with a single x10 scope probe connected to the 465.I can't remember if the 1740 can do this or not... I haven't used one for maybe 20 years. If I see an image of a 1740 I just think of worn out or missing controls on the front panel and I also remember how much I cringed when one of these unreliable old duffers was the only scope I could get immediate access to at work.

author: vk6zgo
author_rank: Super Contributor
timestamp: August 25, 2017, 12:29:08 am
content: Quote from: G0HZU on August 24, 2017, 11:30:26 pmThe "rule of thumb"used to be:-Oscilloscopes, go for Tektronix, & for RF stuff, use HP.It really turned out to be correct on many occasions.When I was at a depot which looked after TV sites across Western Australia, we often carried a Tek 465 or similar, & a HP 180 series mainframe with a Spec An plugin.We could have just carried the ordinary 'scope plug ins, but that would have meant swapping around.The 180series seemed quite a good device, but if you wanted a 'scope, you normally reached for a Tek.I've only used a 1740 a couple of times, & it seemed OK, but I also remember there being a "dead" one sitting around for ages.That Ch 1 output is one of the most useful & versatile things when it is provided.The Iwatsu we had at my later job in Commercial TV had one, too.One of our routine tests was to look at the depth of modulation of the low frequency subcarrier associated with the TV stereo sound system.From memory, the modulation on this was : no mod - mono, one frequency stereo,the other one, dual sound.The subcarrier output from the R & S precision receiver was too low to look at the envelope, so it was into Ch1,then out, & into Ch2.It was still a bit "furry", but you could clearly see & measure the modulation envelope.

author: tggzzz
author_rank: Super Contributor
timestamp: August 25, 2017, 07:25:25 am
content: Quote from: G0HZU on August 24, 2017, 11:08:51 pmThe 1740 timebase PCB switchdoesseem designed to fail - a track becomes abraded by the edge of the switch. Easily repairable, but it shouldn't have to be. And I'm unimpressed by the way the timebase board is supported, but given the connector, it is probably OK.OTOH having pulled a few 465s apart, some of their construction technique seems distinctly tacky as well - components and wires in mid air, fluff/dust/grunge in the exposed non-wiping switch contacts.

author: bd139
author_rank: Super Contributor
timestamp: August 25, 2017, 08:14:21 am
content: Interesting thread. Lots of useful info. You know I've never even looked at the back of the 465B as it was wedged against the wall on my ridiculously small bench. The CH1 out + frequency counter combo is incredibly useful and entirely missing on the 1740. Can't believe I didn't use that. Most of the time I had a 465B/475 and a 5315A on the bench and spent a lot of time probe swapping.Not sure what is worse: the TB switch on the 1740A or the leaf switches on the 4xx scopes. I don't think there's a winner for crapness there. They both work until they don'tI did some measurements yesterday and have noticed that the 1740A is literally the same size as a "3 hole" Tek 7000 except with different orientation. The 7000 takes up less bench footprint which is somewhat precious for me. May use this as an excuse to start collecting 7000 series bits (I can see my wife tutting already)

author: oldway
author_rank: Super Contributor
timestamp: August 25, 2017, 08:15:08 am
content: I have an HP1740A and a 465B, which allows me to make a comparison.These are both excellent analog oscilloscopes.In the 1980s, I worked a long time using an HP1740A, which is why my preference goes for this oscilloscope.We have never had any reliability problems with this oscilloscope.Obviously, 37 years later, this may be different.One of the advantages of the HP1740A is that it does not have a fan.On the other hand, it is very cumbersome.Currently I do the repair of vintage audio equipment (amplifiers, FM tuners, receivers) and I use what I consider to be the best HAMEG oscilloscopes, the HM605.The component tester is one of the essential diagnostic and repair functions that neither the 465B nor the HP1740A have.The Hameo HM605 also has an output of the channel 1 amplifier available at the rear and I also use it to connect a frequency counter.

author: bd139
author_rank: Super Contributor
timestamp: August 25, 2017, 08:28:34 am
content: The 1740A I picked up the other day is in excellent condition. After all the years, visual inspection, calibration, cleanup and it looks and works as good as new. The cal seals were still intact and last cal date was September 1991. Owned by Ferranti apparently based on the asset label. Only problem is on highest sweep the trace is quite dim but that's not unusual.The fan is the problem I have really. I picked up a Rigol DS1054Z and while it's a pretty nice scope, the fan does my head in terribly. I like a silent bench. I can cope with the low hum of a 4xx scope but the Rigol is horrible. On the basis I don't actually want to void the warranty I think I'm going to sell it.My second scope was a Hameg HM203. Nice bit of kit. Agree with the component tester - very useful to have a basic curve tracer built in.

author: G0HZU
author_rank: Super Contributor
timestamp: August 25, 2017, 10:52:42 am
content: QuoteYes, that all seems familiar. At work we eventually got fed up of sending these scopes for repair. I think we had four 100MHz 174x models and the 275MHz version and they were all fragile and unreliable. Our test gear had a hard life back in those days, a scope (or a spectrum analyser or sig gen or VNA) could visit several benches in just one day, sometimes carried, sometimes wheeled on a rattling trolley and this took its toll on the stuff that wasn't designed to survive this kind of use. The Iwatsu scopes were totally reliable year after year and we still had them until recently. They were scrapped through lack of use rather than any failures. But the HP1740 scopes and all the Philips scopes went in the skip some time in the 1990s.If an HP1740 was lightly used and lived its life on a single bench it would probably last a long time without problems. But I never want to use one again because I remember how awful they are to use once the controls begin to wear out or fall off. The timebase control was particularly weak in this respect.

author: bd139
author_rank: Super Contributor
timestamp: August 25, 2017, 12:27:17 pm
content: TBH I've had problems with anything with latching changeover switches in. That includes most HP and Philips kit of the early 1990s and anything Thurlby up to recently. They're just crap switches. The squishy button and signal relays solution actually seems to be better these days.

author: Unknown
author_rank: Unknown
timestamp: August 25, 2017, 06:35:33 pm
content: I worked at HP at the time of the 1740A and the Tek 465 (and later, 465B).I remember the old Tandy company was making PCs - or about to get into the business. They were looking at buying 100 of the 1740As or the 465Bs. We brought them to HP and tore down our 1740A for them to them to see the construction. I assume that Tek did the same thing.Tandy ended up buying the 1740A's.When the scopes were new, the 1740A had a brighter, cleaner trace than the 465B.It had a sealed cabinet while the 465B had a fan.The 1740A took the trigger level voltage before the position control so that trigger level was not affected by the vertical position. But Tek took the trigger voltage after the vertical position control. So if you changed the vertical position, you could lose trigger.The controls on the 1740A were much more rugged and solid-feeling than the 465B. It was obvious when you sat them side by side.I personally liked the layout better. You didn't have to reach to both the left and right sides of the CRT on the HP but you did on the Tek.Also, the HP sold for about 10% less than the Tek.

author: G0HZU
author_rank: Super Contributor
timestamp: August 25, 2017, 09:16:37 pm
content: QuoteThis is just my opinion (based on a career working in RF labs) but the user interface on Tektronix gear from that era was built to last and HP gear from the late 70s onwards wasn't built as well. Maybe HP tried to make gear that lasted but time has proved otherwise. Take a look at any HP gear from that era that had rotary controls and you will see evidence of common failures. Examples of classic instruments with controls that fall apart are the HP8640B sig gen, the HP8569B spectrum analyser and several other analyser models with similar controls. I think the (plastic or nylon?) materials go brittle over time and crack and fail. I can't remember seeing inside the HP174x scopes but I can vaguely remember the fault reports from the cal/repair people. I think the rotary controls use a PCB/contact system that wears out or becomes intermittent and I think the timebase control had various weaknesses. We had about 5 of these scopes and they all went the same way through heavy use.One issue with the 465 is that it may be built to last but it isn't built to be taken apart easily. I'd expect the HP gear to be easier to take apart and the 174x scopes will typically be cheaper to buy used. But just make sure you don't buy one that has worn out rotary controls.QuoteOur 1740 scopes were starting to lose some brightness by the time they were scrapped but the trace quality/sharpness was a strong point on the scope. The trace quality of a typical 465 was always acceptable to me but not great in comparison to other scopes. I only ever saw a few 475 variants but these higher BW scopes were quite fuzzy due the higher BW. So I would advise people to choose the 465 over the 475 unless they need the 200MHz bandwidth it offers.

author: bd139
author_rank: Super Contributor
timestamp: August 25, 2017, 11:12:23 pm
content: The 475 trace isn't that great at all. If you pull the bandwidth limit out progressively it improves things of course. At 20MHz it's nice and crisp. I found I spend most of the time running at 20MHz then knocked it up as required.

author: oldway
author_rank: Super Contributor
timestamp: August 26, 2017, 09:04:36 am
content: Quality and reliability of crt's of HP where as good as TEKTRONIX.HP oscilloscopes had even better performance than TEKTRONIX with the delta time interval HP1743A 100Mhz oscilloscope.And the large screen version of HP1740, the HP1745A, was very nice.