Marconi 2018
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Marconi 2018
I bought two Marconi 2018s at the Newbury rally, both not working and a few keys missing from the keyboard - though not the same keys.
One was £45 sold as "stopped working during storage" and the other was £20 and sold as incomplete.
The incomplete 2018 was missing its Frequency Standard board, but the oscillator was still present. The standard board divides the oscillator by 10,000 to provide a 1kHz reference to the synthesizer and handles the switchover to external clock source, too.
My first job was to see how badly messed up this incomplete unit was, by substituting the Frequency Standard board from the supposedly working one. This didn't make it spring into life. The computer did not appear to be communicating with the other boards, but was running and starting up.
Instead of swapping the board back I decided to board swap it until it worked but first I'd check the capacitors in the PSU.
Sure enough all the small Philips blue capacitors (22µF and 4.7µF) were well down in value (3µF and 1µF respectively), so I changed them. I also took out the chunky 15mF 16V smoothing capacitor for the +5V rail and somehow managed to misread it as 18.5µF, so I changed it. Later I put my glasses on and discovered that it was actually 18.5mF, I'd forgotten that the small tester I was using switches to milliFarads. I had tested the small capacitor on my Wayne Kerr B605 so I'm not sure why I didn't test the big one on that, too, but it was hot and I was tired and my vision was blurry.
I decided that as the computer comms problem was preventing anything from happening and limiting my diagnostic options I'd switch back to the other supposedly nearly working unit. This turned out to be not really the case, in many ways, but the computer *was* working and so was the front panel and something was appearing on the display. The output, though, was nothing because the reverse power protection was triggering once the computer finished booting. Removing the connector that contained the input to the RPP measurement diodes allowed it to boot but it was clear that the display wasn't right.
I decided to use the rebuilt-PSU generator as the project and the "working" 2018 as the donor, the deciding factor being the "working" PSU which had been modified for no obvious reason so the +5V adjustment range started at 5.25V and went up to around 7V, which I thought may have damaged some TTL or one of the divider ICs. This turned out not to be a particular problem but a duff keyswitch sealed the fate of the front panel and later I discovered that the frequency display had some bad segments (could be the decoder/driver chip).
With the Frequency Standard board now moved back to the more broken of the two I found that it would occasionally boot. Changing the CPU and reseating the EPROMs seemed to make it better but it always started up with an error indicating a bad checksum in the EAROM.
I also had no synthesizer lock, but it was switching between oscillators. There was no output on the front panel, though, only at the intermediate point where the RF comes from the synthesizer into the AM/filter/amplifier box. I took the easy way out at this point and substituted two divider boards in the synthesizer which brought back the fine steps but only above 32.5MHz. This meant that the BFO circuit was not doing its thing, so I changed that and got 80kHz to 32.5MHz back. The attenuator on this one seemed to be fine, though the output levels were all wrong, it was at least going through 10dB steps as it should.
Then I tried FM, but there was no FM at all. It seems that with an empty or corrupt FM calibration table the generator can't do FM. Additionally there seemed to be a problem with the FM/modulation oscillator board, so I swapped that over, too. After a very long calibration process with my trusty (slightly broken) 2305 I had working FM.
Now it was time to look at the output level, which seemed not awful on the BFO output but very poor at the UHF end, even with the calibration cranked up all the way. The output amplifier board had been modified due to excessive gain. Rather than back the mod out I just changed it and this brought back full level adjustment and amplitude calibration was a success with plenty of gain in hand. I didn't realise before, but these generators can easily do +20dBm with a bit of deliberate mis-calibration. AM calibration also worked but I wasn't able to stop it being a few percent over at UHF, so I may revisit that soon.
The front panel needed attention so I put together the best switch caps from both to give it a full set. Two LEDs were also not working, the AM indicator and the 6kHz modulation oscillator indicator. I changed both multiple times, turns out the + symbol on the silkscreen is on the cathode. No idea why but not the first time I've seen this on test equipment. I didn't have any 2mm LEDs for the 6kHz indicator or proper yellow 3mm for the AM switch, but I managed to pull the 2mm LED from the other front panel and have used a sort of orangey LED instead of yellow for the AM switch. It's actually the same colour as the switch, which almost made me change all of them…
I'm now trying to get the donor unit working to some extent, as I am sure I can bodge a Frequency Standard board quite easily and I'd like to get board level fixes done where possible.
I had originally intended to sell the 2018 at McMichael but it wasn't ready in time - just the LEDs, really, but I'd worn myself out and had little sleep, hadn't managed to get to to the storage unit to grab some other items I wanted to sell. I may make it to MK to sell, though. I'm definitely keen on getting rid of my 853/8558 (with bonus broken 8559 and incomplete 8557 in flatpack form), possibly my 3325B, because it's a hateful thing that breaks whenever I need it, some Fluke 8502 ac meters, maybe my RACAL 1992 and 9300B and a few boxes of components that I'll never use. Not sure it'll fit in the Fiat 500, though…
One was £45 sold as "stopped working during storage" and the other was £20 and sold as incomplete.
The incomplete 2018 was missing its Frequency Standard board, but the oscillator was still present. The standard board divides the oscillator by 10,000 to provide a 1kHz reference to the synthesizer and handles the switchover to external clock source, too.
My first job was to see how badly messed up this incomplete unit was, by substituting the Frequency Standard board from the supposedly working one. This didn't make it spring into life. The computer did not appear to be communicating with the other boards, but was running and starting up.
Instead of swapping the board back I decided to board swap it until it worked but first I'd check the capacitors in the PSU.
Sure enough all the small Philips blue capacitors (22µF and 4.7µF) were well down in value (3µF and 1µF respectively), so I changed them. I also took out the chunky 15mF 16V smoothing capacitor for the +5V rail and somehow managed to misread it as 18.5µF, so I changed it. Later I put my glasses on and discovered that it was actually 18.5mF, I'd forgotten that the small tester I was using switches to milliFarads. I had tested the small capacitor on my Wayne Kerr B605 so I'm not sure why I didn't test the big one on that, too, but it was hot and I was tired and my vision was blurry.
I decided that as the computer comms problem was preventing anything from happening and limiting my diagnostic options I'd switch back to the other supposedly nearly working unit. This turned out to be not really the case, in many ways, but the computer *was* working and so was the front panel and something was appearing on the display. The output, though, was nothing because the reverse power protection was triggering once the computer finished booting. Removing the connector that contained the input to the RPP measurement diodes allowed it to boot but it was clear that the display wasn't right.
I decided to use the rebuilt-PSU generator as the project and the "working" 2018 as the donor, the deciding factor being the "working" PSU which had been modified for no obvious reason so the +5V adjustment range started at 5.25V and went up to around 7V, which I thought may have damaged some TTL or one of the divider ICs. This turned out not to be a particular problem but a duff keyswitch sealed the fate of the front panel and later I discovered that the frequency display had some bad segments (could be the decoder/driver chip).
With the Frequency Standard board now moved back to the more broken of the two I found that it would occasionally boot. Changing the CPU and reseating the EPROMs seemed to make it better but it always started up with an error indicating a bad checksum in the EAROM.
I also had no synthesizer lock, but it was switching between oscillators. There was no output on the front panel, though, only at the intermediate point where the RF comes from the synthesizer into the AM/filter/amplifier box. I took the easy way out at this point and substituted two divider boards in the synthesizer which brought back the fine steps but only above 32.5MHz. This meant that the BFO circuit was not doing its thing, so I changed that and got 80kHz to 32.5MHz back. The attenuator on this one seemed to be fine, though the output levels were all wrong, it was at least going through 10dB steps as it should.
Then I tried FM, but there was no FM at all. It seems that with an empty or corrupt FM calibration table the generator can't do FM. Additionally there seemed to be a problem with the FM/modulation oscillator board, so I swapped that over, too. After a very long calibration process with my trusty (slightly broken) 2305 I had working FM.
Now it was time to look at the output level, which seemed not awful on the BFO output but very poor at the UHF end, even with the calibration cranked up all the way. The output amplifier board had been modified due to excessive gain. Rather than back the mod out I just changed it and this brought back full level adjustment and amplitude calibration was a success with plenty of gain in hand. I didn't realise before, but these generators can easily do +20dBm with a bit of deliberate mis-calibration. AM calibration also worked but I wasn't able to stop it being a few percent over at UHF, so I may revisit that soon.
The front panel needed attention so I put together the best switch caps from both to give it a full set. Two LEDs were also not working, the AM indicator and the 6kHz modulation oscillator indicator. I changed both multiple times, turns out the + symbol on the silkscreen is on the cathode. No idea why but not the first time I've seen this on test equipment. I didn't have any 2mm LEDs for the 6kHz indicator or proper yellow 3mm for the AM switch, but I managed to pull the 2mm LED from the other front panel and have used a sort of orangey LED instead of yellow for the AM switch. It's actually the same colour as the switch, which almost made me change all of them…
I'm now trying to get the donor unit working to some extent, as I am sure I can bodge a Frequency Standard board quite easily and I'd like to get board level fixes done where possible.
I had originally intended to sell the 2018 at McMichael but it wasn't ready in time - just the LEDs, really, but I'd worn myself out and had little sleep, hadn't managed to get to to the storage unit to grab some other items I wanted to sell. I may make it to MK to sell, though. I'm definitely keen on getting rid of my 853/8558 (with bonus broken 8559 and incomplete 8557 in flatpack form), possibly my 3325B, because it's a hateful thing that breaks whenever I need it, some Fluke 8502 ac meters, maybe my RACAL 1992 and 9300B and a few boxes of components that I'll never use. Not sure it'll fit in the Fiat 500, though…
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Re: Marconi 2018
Interesting and a post worth noting for the future. I eyed up those two 2018s at Newbury and heard the patter about one being incomplete, but the dearer one only needed the boards wiggled. I was tempted. There was another 2018 on the stall next door for £70, as I recall. I don't know what claims the seller was making. There was a fourth in the back of an estate car.
I have a working 2019 which I use, and a 2019 I bought as a spare, which is mainly working but has problems. The keys and LCDs on those act up and the frequency references very likely weren't great when they were new, and have not aged well. They are nice sig gens, but they are big, which is part of why I could resist the pair at Newbury. Had they been 2019s it would have tipped the balance.
I have a working 2019 which I use, and a 2019 I bought as a spare, which is mainly working but has problems. The keys and LCDs on those act up and the frequency references very likely weren't great when they were new, and have not aged well. They are nice sig gens, but they are big, which is part of why I could resist the pair at Newbury. Had they been 2019s it would have tipped the balance.
Re: Marconi 2018
It's quite tempting to populate the doubler and flip the bit in the configuration that tells it that it's a 2019 and not a 2018. The RF amplifier is capable of the full frequency range and there's an extra calibration point for setting the levelling from 520 to 1040MHz.
Re: Marconi 2018
It's amazing the number of things where the much more expensive de luxe high performance version, is very little different from the standard one. e.g. Siglent and Rigol TE, where the right licence codes turn the bottom of the range into the top of the range, with all options available.
I suppose the electronics industry has always sold a guaranteed specification, and how they do it is their business. The earliest example I can think of is from around 1930 when a U12 and U14 rectifier looked the same but the U12 had a specified voltage of 350 and the U14 500. Now there may have been differences in materials, or U12 was only tested to 350V, or all U12 and U14 tested to well over 500V, and they marked them differently to suit market demands.
I suppose the electronics industry has always sold a guaranteed specification, and how they do it is their business. The earliest example I can think of is from around 1930 when a U12 and U14 rectifier looked the same but the U12 had a specified voltage of 350 and the U14 500. Now there may have been differences in materials, or U12 was only tested to 350V, or all U12 and U14 tested to well over 500V, and they marked them differently to suit market demands.
Re: Marconi 2018
Tektronix and HPAK have been doing it for decades. I bought my Tektronix TDS3032 oscilloscope in about 2000 and on one of the firmware updates I discovered it was sampling at 5GS/s rather than maximum of 2.5GS/s that I'd paid for. The next firmware update "corrected" that. If you buy a bottom-of-the-range Tektronix, HPAK, or R&S oscilloscope, you can upgrade its bandwidth from 300MHz to 500MHz or 1GHz with a licence code; the top-of-the-range front-end is there already. Likewise, you can upgrade the maximum record length with a licence code; the memory is there already. They just make one oscilloscope, then hobble it for different price points. I can see that it makes for economies of scale to make a single instrument and tailor it by firmware, but it raises serious questions about the actual cost of production, the selling price, and what you're paying for. I can't help feeling that the major manufacturers set prices by what the market has historically withstood and that they operate as a cartel. Have you noticed that you have to pay a premium to get AC RMS as an automated measurement or the ability to average across FFTs? Neither is an expensive calculation, but oscilloscope ranges have been deliberately structured in that way. As the engineers who accepted that (analogue) bandwidth genuinely cost money to make die away/retire, that tolerance of artificial pricing is withering and much cheaper oscilloscopes are probably bought by Generation Z. That's all well and good if those cheaper oscilloscopes are genuinely as good. The problem there is that not all oscilloscope deficiencies show up in the specifications, so a cheap Siglent (for instance) produced a very poor FFT compared to my TDS3032 because of sampling clock jitter. Real-time capture rates can be slow because the computer is too slow to keep up with data production from the front end. By setting their prices artificially high, the major manufacturers may well be able to please the short-term aims of their bean counters but it's a poor long-term strategy and encourages design/production inefficiencies that will lead to their eventual collapse. And that's a bad thing.
Turning to U12 and U14 rectifiers, have a read of "The Saga of Marconi Osram Valve". It's a very good book written by two engineers who worked there and there are lots of snippets about how valves were made. In one of the transmitting valve sections, there's a piece about how valves were cleaned up after manufacture to allow them to tolerate higher voltages. The Marconi valve book is best read in conjunction with "The Oxide-coated Cathode" (Vol. 1) by Wagener which is quite hard to find as a paper copy, but both volumes are on the World History site that has Wireless World.
Turning to U12 and U14 rectifiers, have a read of "The Saga of Marconi Osram Valve". It's a very good book written by two engineers who worked there and there are lots of snippets about how valves were made. In one of the transmitting valve sections, there's a piece about how valves were cleaned up after manufacture to allow them to tolerate higher voltages. The Marconi valve book is best read in conjunction with "The Oxide-coated Cathode" (Vol. 1) by Wagener which is quite hard to find as a paper copy, but both volumes are on the World History site that has Wireless World.
Re: Marconi 2018
They aren't alone, of course.EC8010 wrote: ↑Sun Jul 19, 2026 10:36 am Tektronix and HPAK have been doing it for decades. I bought my Tektronix TDS3032 oscilloscope in about 2000 and on one of the firmware updates I discovered it was sampling at 5GS/s rather than maximum of 2.5GS/s that I'd paid for. The next firmware update "corrected" that.
...
but it raises serious questions about the actual cost of production, the selling price, and what you're paying for.
...
By setting their prices artificially high, the major manufacturers may well be able to please the short-term aims of their bean counters but it's a poor long-term strategy and encourages design/production inefficiencies that will lead to their eventual collapse. And that's a bad thing.
In the 60s IBM sold their 360 mainframes using a very wide range of implementation technologies, and promising an upgrade path as customer's requirements increased. IIRC the rule of thumb was that cost=k*performance2.
In some cases the performance was increased simply by removing a link on the backplane.
Re: Marconi 2018
It's a marketing strategy that may appear dishonest but has stood the test of time. The manufacturer sells you a specification and is willing to stand by it. They mainly sell to other manufacturers, or the military, or other large organisations. Does anyone seriously want the prospect of facing a disciplinary hearing, or court of law, or court martial because they used a part which was under spec (but their testing showed, and it was common knowledge they were the same) failed and could be accused of causing a disaster, to save a few quid, not of their own money? Large companies dealing with other large companies are in a position to negotiate these things.EC8010 wrote: ↑Sun Jul 19, 2026 10:36 am Tektronix and HPAK have been doing it for decades. I bought my Tektronix TDS3032 oscilloscope in about 2000 and on one of the firmware updates I discovered it was sampling at 5GS/s rather than maximum of 2.5GS/s that I'd paid for. The next firmware update "corrected" that. If you buy a bottom-of-the-range Tektronix, HPAK, or R&S oscilloscope, you can upgrade its bandwidth from 300MHz to 500MHz or 1GHz with a licence code; the top-of-the-range front-end is there already. Likewise, you can upgrade the maximum record length with a licence code; the memory is there already. They just make one oscilloscope, then hobble it for different price points. I can see that it makes for economies of scale to make a single instrument and tailor it by firmware, but it raises serious questions about the actual cost of production, the selling price, and what you're paying for. I can't help feeling that the major manufacturers set prices by what the market has historically withstood and that they operate as a cartel. Have you noticed that you have to pay a premium to get AC RMS as an automated measurement or the ability to average across FFTs? Neither is an expensive calculation, but oscilloscope ranges have been deliberately structured in that way. As the engineers who accepted that (analogue) bandwidth genuinely cost money to make die away/retire, that tolerance of artificial pricing is withering and much cheaper oscilloscopes are probably bought by Generation Z. That's all well and good if those cheaper oscilloscopes are genuinely as good. The problem there is that not all oscilloscope deficiencies show up in the specifications, so a cheap Siglent (for instance) produced a very poor FFT compared to my TDS3032 because of sampling clock jitter. Real-time capture rates can be slow because the computer is too slow to keep up with data production from the front end. By setting their prices artificially high, the major manufacturers may well be able to please the short-term aims of their bean counters but it's a poor long-term strategy and encourages design/production inefficiencies that will lead to their eventual collapse. And that's a bad thing.
I've no idea how much Siglent and Rigol sell to large organisations vs amateurs. I assume that professionals buy a piece of gear, use it and it goes off for calibration as a matter of routine. Then after a few years, it's sold off. They are not going to mess about with unauthorised modifications because they are not. Amateurs, OTOH are not going to buy this stuff unless they know they can adjust the lowest price option to be the highest priced option, and they'll take their chance on whether it remains in calibration and the effect on the warranty. In some cases there's an official upgrade path from the lowest to the highest, and in others there isn't, so there may be actual differences in the hardware, possibly revealed by factory testing.
I guess that HPAK, R&S, Tek etc, mainly sell to to large organisations, which are not cost sensitive and where they have lock in anyway. I assume their products are better, and for the price difference, they certainly ought to be.
I was always intrigued by 1N4001 to 1N4007 rectifiers which came out in the early 60s. I wondered if there was ever a difference, or whether they'd all pass the tests for a 1N4007. For years there's been little or no difference in price, and you may as well use 1N4007 and forget the rest.
Re: Marconi 2018
I don't agree with your argument about pricing, but I accept that it's a valid argument. When you paid extra for more bandwidth on a valve oscilloscope, it was because it genuinely cost more to get that bandwidth, and that was honest trading. That's not true now it's all on a chip. I have learned when buying stuff for myself to buy the bottom model of the highest range I can afford, so my Tek oscilloscope is a paltry 300MHz when it could be 1GHz. I rarely use it at time bases faster than 1s/div. I suspect Rigol are more targetted towards amateurs.
Depends. At the Beeb, we bought stuff and it was never recalibrated in its entire life. But to be fair, the standards for measuring video were quite low, so superlative accuracy wasn't necessary. When I was in teaching, the main criterion was robustness. In my final job, we did send some stuff away to be calibrated, but it was only one out of each type of instrument. Our lab probably had about twenty 6 1/2 digit DMMs, three electrometers, a current source, one LCR bridge, and a few odds and ends, so one of each went away for annual calibration. I've never worked in a lab where equipment was sold off; if it went, it went in a skip and it would be at least twenty years old by that time. Probably with scorch marks somewhere. Agreed that it was uncommon to modify commercial equipment. In final job, if a standard piece of equipment couldn't do what we wanted, we designed and made something from scratch.
Point noted about 1N4001 vs 1N4007. I've certainly got some 1N4007, but whether I have anything lower voltage, I've no idea. If I have, I may do some measuring to see if there's genuinely a difference.
Re: Marconi 2018
Tek 465, 475 and 485 were genuinely different. That's the early 70s.
If you look at Hitachi scopes, which came along when the technology was better developed, and 20MHz dual trace scopes were more or less a commodity, say mid 80s, the apparent difference between the 20MHz Y amps and the 60MHz Y amps was a few small capacitors. Well the 40 plus MHz versions had a higher EHT, maybe a different CRT and maybe there was sufficient variation in manufacturing that they knew only so many boards were capable of 60MHz.
Valve scopes were different. A Solartron CD1400 from the mid 60s cost well over £500, I believe, and had a bandwidth of 15MHz. By then Tek had sampling plugins good for 1GHz. Tek and HP were more or less committed to going for the high end of the food chain. I think HP gave up on analogue scopes around 1980. Tek stuck with them longer because their business was more about scopes.
By 1970, scopes were things amateurs longed for but few bought. There were few about, probably ex-military. I have a few, which I bought for junk prices around 2000. In 1970 they would have been dream machines for the average reader of Practical Electronics.
It's always been clear to me that specsmanship and status was a large part of scope sales.EC8010 wrote: ↑Wed Jul 22, 2026 4:32 pm That's not true now it's all on a chip. I have learned when buying stuff for myself to buy the bottom model of the highest range I can afford, so my Tek oscilloscope is a paltry 300MHz when it could be 1GHz. I rarely use it at time bases faster than 1s/div. I suspect Rigol are more targetted towards amateurs.
I've no idea how Siglent and Rigol sales are divided between amateurs and professionals, but I'd like to know. They know perfectly well that their hobbling methods have been defeated and don't really care. They don't seem to have tried hard to improve it. It's a tolerated lliegality which works to their advantage. Photoshop, which was a superior product, was available as a trial version which was easily hacked. Graphics design students used the hacked version and were familiar with it. When they got jobs, they asked for it and were good with it. Their employers weren't going to force them to use something else, and they weren't going to risk using the hacked version.
40 years back there were companies that had a use for a scope of some sort, but they didn't need to splash out on a Tek or HP. I have a 20MHz Hameg with burned in company markings.
Selling the same product in different guises has gone on for a long time. tggzz mentioned the IBM computer enhanced by cutting a few links. I mentioned the U12/U14 rectifiers. I suspect the practice was well established before then. Software makes it easier.
Re: Marconi 2018
Currently the greatest % of our NZ sales of Siglent are to business....so pro use if you like.Zenith wrote: ↑Wed Jul 22, 2026 7:37 pm .................
It's always been clear to me that specsmanship and status was a large part of scope sales.
I've no idea how Siglent and Rigol sales are divided between amateurs and professionals, but I'd like to know. They know perfectly well that their hobbling methods have been defeated and don't really care. They don't seem to have tried hard to improve it. It's a tolerated illegality which works to their advantage.
..........
Unauthorized BW and option licensing for the lower cost models is easy as V1 licensing is used and Python scripts are available online to accomplish license code generation.....yet we sell these to both hobbyist and business use.
The higher cost professional products OTOH use V2 licensing which with some effort can be cracked but there are no online scripts available yet.....so sorta locked up tight for now making a clear distinction between hobbyist and pro models.
Siglent Distributor NZ, TE Enabler
Re: Marconi 2018
Sadly, I fear you are correct there. When I was working, a colleague had a 'scope the next range up from mine, but I don't think he ever exercised its true capabilities.
Re: Marconi 2018
But you don't know what's happened with them over the years and you don't know what the maker knows.
For instance, they may have been physically different when they were first produced in the 60s. They may have been improved so 70% or even 100% pass as 1N4007. They may differ from maker to maker. So a test of a specific batch wouldn't give reliable information about 1N4001/7 in general.
I don't use that many 1N4007s. I've got a hundred or so I saw going cheap at a rally. I've also got a big bag of 1N4004s with cropped leads which came in a job lot.
Re: Marconi 2018
And then there is moving devices to new processes. Usually that won't matter, but
- modern 2N3055s can oscillate due to higher bandwidth
- https://www.eevblog.com/forum/blog/eevb ... msg6276104
- some op amps have had the input offet control pins removed(!), possibly when moved to a cmos process?
Re: Marconi 2018
In the 60s and 70s when silicon transistors were hot news, and presumably makers thought they could get an edge by offering something they could claim was different, there were literally thousands of types. Large numbers were interchangeable in most applications. Now there are maybe a couple of hundred through hole parts in production.
BC107/8/9. 107 was guaranteed to take a ce voltage of 45V. 109 was guaranteed to have a 2dB noise figure, 108 was general purpose. They could be bought as either unsorted, or sorted into gain groups A,B and C. I have a Marconi TF2331 distortion meter. Some of the transistors were socketed so you could select transistors less noisy than the BSX20 fitted in the factory. I tried several including BC109. A batch of BC108 from Maplin were the best. There were some particularly low noise Hitachi transistors which Maplin had stopped selling a few months before.
Then they were sold in different packaging, BC147/8/9 and later BC547/8/9, also available sorted into gain groups. There were loads of very similar ones designated BCxxx, 2Nxxxx and several others. Some were obviously different, such as high voltage and high frequency types. Some of the once common high frequency types have disappeared because the action has moved to ICs and SMT.
Tek, HP etc, did their own selecting for critical positions, so a 151-xxxx-00 would be a 2NYYYY, but selected for high fT and high gain, say. Bunging in a 2N3906 will usually work a bit, but not give full performance.
BC107/8/9. 107 was guaranteed to take a ce voltage of 45V. 109 was guaranteed to have a 2dB noise figure, 108 was general purpose. They could be bought as either unsorted, or sorted into gain groups A,B and C. I have a Marconi TF2331 distortion meter. Some of the transistors were socketed so you could select transistors less noisy than the BSX20 fitted in the factory. I tried several including BC109. A batch of BC108 from Maplin were the best. There were some particularly low noise Hitachi transistors which Maplin had stopped selling a few months before.
Then they were sold in different packaging, BC147/8/9 and later BC547/8/9, also available sorted into gain groups. There were loads of very similar ones designated BCxxx, 2Nxxxx and several others. Some were obviously different, such as high voltage and high frequency types. Some of the once common high frequency types have disappeared because the action has moved to ICs and SMT.
Tek, HP etc, did their own selecting for critical positions, so a 151-xxxx-00 would be a 2NYYYY, but selected for high fT and high gain, say. Bunging in a 2N3906 will usually work a bit, but not give full performance.
It's a known problem with Tek 400 series, that modern 2N3055s can misbehave because of higher bandwidth. There are also fake 2N3055s around.modern 2N3055s can oscillate due to higher bandwidth
Re: Marconi 2018
I wonder why they changed tack.
Is it your experience that professional buyers use unauthorised licences? My guess is that they typically wouldn't for a host of reasons.
Re: Marconi 2018
When they went upmarket with the SDS5000X series with models to 1 GHz there was some increased interest as the lowest 350 MHz model could be BW upgraded to 1 GHz, evident by the formal and authorized $ $ BW upgrade path.
V1 licensing was used in SDS5000X at release but was changed to V2 with a FW update to better protect their income stream.
Currently V2 licensing now starts with the 12bit SDS2000X HD models but the 8bit SDS2000X Plus models have retained V1 licensing and 2k models all have a formal BW upgrade path like their bigger brothers.
No doubt some pro's hack but they're normally one man bands with shallow pockets whereas the real pro's cough up for the BW and optional features they need.
One of the features I really like is all models from the $356 2ch 70 MHz SDS802X HD use the same GUI which offers a low cost entry point to the Siglent way of scope use.....webserver, touch, mouse control etc.
Driving the top model is essentially the same but of course with a much greater feature set.
Siglent Distributor NZ, TE Enabler
Re: Marconi 2018
That's what I suspected. Startups and very small companies might sail close to the wind, but established companies, the military and government departments, have no incentive to make unauthorised modifications and it might carry serious consequences.
Re: Marconi 2018
It is also possible and reasonable to use low end scopes for simple sanity checking and fault-finding, reserving better equipment for subtle investigations and formal performance assessments.
Bit like using a 3.5 digit DVM swell as a 6.5 digit DVM.
Re: Marconi 2018
Yeah but what would you do in my position ?
As a model range shares the exact same HW but BW gets limited by SW code to control the VGA just like it does with the 20 MHz BW limit, one can hardly accuse an owner of a hack like the HW mods of yesteryear.
Turning a blind eye has been my MO and they keep coming back for more products having saved a few bucks not needing to purchase options.
Siglent Distributor NZ, TE Enabler
Re: Marconi 2018
I'd probably do what you are doing, unless there was a lot of pressure from Siglent not to.
I'm not sure what happens if an instrument sold as bottom of the line, but has unofficial licence code updates, fails under warranty. Presumably Siglent or the dealer is entitled to refuse to honour the warranty. It doesn't make sense for the dealer to make waves. Hardware mods would be different.
Siglent must know perfectly well that there are means to generate unauthorised licence keys around, mainly used by amateurs. They can't say they approve, but they don't disapprove very strongly, because it generates more sales. That's why I don't really understand why they've turned to V2 licensing for their new higher end items. I believe it's been reverse engineered, but Siglent have asked the reverse engineers not to make it public.
Back in the day, people would unlawfully take MSDOS, MS Word etc discs from work and install them on their home PCs. I think it worked out in Microsoft's favour. A senior figure at Microsoft is supposed to have said something along the lines of, "If they are going to pirate software, I want it to be our software". I think it reinforced the assumption that all PC software was Microsoft software.
I'm not sure what happens if an instrument sold as bottom of the line, but has unofficial licence code updates, fails under warranty. Presumably Siglent or the dealer is entitled to refuse to honour the warranty. It doesn't make sense for the dealer to make waves. Hardware mods would be different.
Siglent must know perfectly well that there are means to generate unauthorised licence keys around, mainly used by amateurs. They can't say they approve, but they don't disapprove very strongly, because it generates more sales. That's why I don't really understand why they've turned to V2 licensing for their new higher end items. I believe it's been reverse engineered, but Siglent have asked the reverse engineers not to make it public.
Back in the day, people would unlawfully take MSDOS, MS Word etc discs from work and install them on their home PCs. I think it worked out in Microsoft's favour. A senior figure at Microsoft is supposed to have said something along the lines of, "If they are going to pirate software, I want it to be our software". I think it reinforced the assumption that all PC software was Microsoft software.
Re: Marconi 2018
There's nothing preventing a user modifying any equipment.
Noticeable problems arise if
- there is a warranty claim. I guess siglent has a policy on what happens, and you follow that.
- modified or uncalibrated equipment is used to falsely certify a product. Not your problem; user is clearly wrong.
Re: Marconi 2018
Of course they know, they followed Rigol in leaving the doors open to hacks of the lower cost models.Zenith wrote: ↑Fri Jul 24, 2026 12:40 pm ............
Siglent must know perfectly well that there are means to generate unauthorised licence keys around, mainly used by amateurs. They can't say they approve, but they don't disapprove very strongly, because it generates more sales. That's why I don't really understand why they've turned to V2 licensing for their new higher end items. I believe it's been reverse engineered, but Siglent have asked the reverse engineers not to make it public.
...............
V2 licensing is an entirely different story and quite different for each model series where only analysis of an instruments memdump can find the algorithm that allows for license generation.
Currently there is just one keyholder and he's keeping the door shut as he like us has witnessed how far the brand has come in just a few years and how far they could go on to keep mowing the grass of the A brands.
Ongoing product development like we've seen in the last decade costs real coin so to go public with hacks for the higher cost models will stifle development and let the A brands carry on without a care.
Which would you prefer ?
Siglent Distributor NZ, TE Enabler
Re: Marconi 2018
If the HW fails any mods become invisible if you can't boot the instrument.tggzzz wrote: ↑Fri Jul 24, 2026 12:53 pmThere's nothing preventing a user modifying any equipment.
Noticeable problems arise if
- there is a warranty claim. I guess siglent has a policy on what happens, and you follow that.
- modified or uncalibrated equipment is used to falsely certify a product. Not your problem; user is clearly wrong.
Siglent Distributor NZ, TE Enabler