Test Equipment Anonymous (TEA) group therapy thread

[Vince]

Some of the other lots I collected today, spent a bit of time removing the auction labels this afternoon.

Tek 109 pulse gen, originally used by Tek in the UK site according to the back.

David

Murphy again... in a good way though for a change.
Just when Factory shows us this adorable, sweet cute little 109 pulser.... here is another on the same theme. Another little Tek portable in the same form factor. A 107 fast square wave generator, in the latest Carlson's Lab video that just landed :

Nice video I found, only 28 minutes, just good stuff I found.

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Weird : just checked the Tekwiki page about this 107.

https://w140.com/tekwiki/wiki/107

Strangely, the description pretends it's 50 ohms not 52... and it's not a typo either : they say it multiple times.. even though the face plate of the instrument clearly reads 52 not 50, and the service manual spec page says 52, the schematic says 52 too... it's 52 not 50 !

Worse : Tekwiki goes on to give an explanation of why it's 50 ohms (when it's not), it goes : " It's 50 ohms because the plate load resistor of the output/driver tube is 50 ohms ".   

Eh ?!  As you can see in the schematic, the plate resistor for the output tube is hardly 50ohms, far from that, it's 100+ times more, it's 5.6K !!

[mnementh]

*Dura-leaks were removed after testing,

David

There is still a bug in the system somewhere, when clicking on the last photo of the meter dial to see the AVO logo, I get a portion of the bottom right hand section of the photo blanked out     Anyone else getting the same?

2 different pics, buddy.

mnem
 

[AVGresponding]

I've got a near UV lamp somewhere, will have to give that a try, nothing for near-IR though.


David

For the near-IR, you can strip an IR-LED out of a remote-control from an old TV or w/e, then shoot in the dark, with the flash suppressed on your smartphone.

[Vince]

I see yours has a blue CRT... AGAIN ! You appear to have a talent to find these rare beauties...

That's not a blue CRT. It's a blue filter. I've since taken that filter and put it on the Type 547. I wish I could find another one. Plenty of grey and green filters but blue ones are rare.

OK ! How stupid I look now ! All that time I thought your 547 had a blue CRT and I was jealous ! 

Looking at my old pics of my 502A which does have a blue CRT, indeed it looks much different than your blue filter. Blue CRT has a deep black background and very intense contrasting blue. How you managed to fool me I don't know, I feel stupid now 

For my defense, I would say that my 502A is the only blue CRT I have in my 20+ collection of glowing Tek scopes, that I bought it 3 years ago now, that when I got it back then, I played with it for only ONE single day not more, before having to put it in storage with every thing else, as I had to move home.

Have not had an opportunity to power it a second time since then ! 

Here are a couple of the pics I took back then. Indeed looks very different to your green 547 with blue filter (looking at your (main/restored) 547 pics from a few pages back).

[Cerebus]

I see yours has a blue CRT... AGAIN ! You appear to have a talent to find these rare beauties...

That's not a blue CRT. It's a blue filter. I've since taken that filter and put it on the Type 547. I wish I could find another one. Plenty of grey and green filters but blue ones are rare.

If you're not fussed about authenticity then I'm sure you could get something appropriate from Lee Filters http://www.leefilters.com/lighting/colour-list.html and they've got about 20 dealers in NY and I've had no trouble getting their filters off eBay. It's the lighting filters ('gels') you want to be looking at.

[Brumby]

   Urrrghhh... my son just discovered Knight Rider.  Of course I watched it with him. 

My 3 boys are all Knight Rider fans and all have models of it complete with the working scanner, one of them knows a person who actually has a Knight Rider, well a Transam that externally has turned into a KR clone and is now tackling the interior. One day I might get some photos of said car when its completed.

Aside from watching the series when it ran back in the day, this is my only demonstration of interest in it...



Hmmm .... It's not doing what it should.  Let me check on what's wrong.
Edit: It works locally.  Does this forum have a gif aversion?

YAY!  Got it!

[tautech]

Some of the other lots I collected today, spent a bit of time removing the auction labels this afternoon.

Tek 109 pulse gen, originally used by Tek in the UK site according to the back.

David

Murphy again... in a good way though for a change.
Just when Factory shows us this adorable, sweet cute little 109 pulser.... here is another on the same theme. Another little Tek portable in the same form factor. A 107 fast square wave generator, in the latest Carlson's Lab video that just landed :

Nice video I found, only 28 minutes, just good stuff I found.

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Weird : just checked the Tekwiki page about this 107.

https://w140.com/tekwiki/wiki/107

Strangely, the description pretends it's 50 ohms not 52... and it's not a typo either : they say it multiple times.. even though the face plate of the instrument clearly reads 52 not 50, and the service manual spec page says 52, the schematic says 52 too... it's 52 not 50 !

Worse : Tekwiki goes on to give an explanation of why it's 50 ohms (when it's not), it goes : " It's 50 ohms because the plate load resistor of the output/driver tube is 50 ohms ".   

Eh ?!  As you can see in the schematic, the plate resistor for the output tube is hardly 50ohms, far from that, it's 100+ times more, it's 5.6K !!

Yeah but Vince the plate output is coupled so it's impedance is effectively removed so the 100R in parallel with 110R at the output dominate.

[med6753]

Sure, but it's not what Tekwiki said. Again, it said the PLATE/load resistor was 50 ohms. It's not, it's 5.6K.  It's factual, see schematic.

Also said, again that this plate resistor was determining the output impedance, again wrong. Of course as you just said it's determined by the 100/110 resistor // pair further downstream, not by the plate resistor.

Also said it was 50 ohms, but it's 52.

Just factually wrong 3 times. What the article says seems clear to me, no ambiguity in what they mean. And what they mean is just, factually wrong...
This article has me baffled I must say 

No big deal, but from now on I will Tek their articles with a grain of salt...

It's a little known fact that the characteristic impedance of Tektronix male BNC's are actually closer to 52 ohms.

[med6753]

I see yours has a blue CRT... AGAIN ! You appear to have a talent to find these rare beauties...

That's not a blue CRT. It's a blue filter. I've since taken that filter and put it on the Type 547. I wish I could find another one. Plenty of grey and green filters but blue ones are rare.

If you're not fussed about authenticity then I'm sure you could get something appropriate from Lee Filters http://www.leefilters.com/lighting/colour-list.html and they've got about 20 dealers in NY and I've had no trouble getting their filters off eBay. It's the lighting filters ('gels') you want to be looking at.

Good info, thanks. 

[med6753]

OK ! How stupid I look now ! All that time I thought your 547 had a blue CRT and I was jealous ! 

Oculus is the one who has the blue phosphor Type 547.

[Vince]

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it a " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Weird : just checked the Tekwiki page about this 107.

https://w140.com/tekwiki/wiki/107

Strangely, the description pretends it's 50 ohms not 52... and it's not a typo either : they say it multiple times.. even though the face plate of the instrument clearly reads 52 not 50, and the service manual spec page says 52, the schematic says 52 too... it's 52 not 50 !

Worse : Tekwiki goes on to give an explanation of why it's 50 ohms (when it's not), it goes : " It's 50 ohms because the plate load resistor of the output/driver tube is 50 ohms ".   

Eh ?!  As you can see in the schematic, the plate resistor for the output tube is hardly 50ohms, far from that, it's 100+ times more, it's 5.6K !!

Yeah but Vince the plate output is coupled so it's impedance is effectively removed so the 100R in parallel with 110R at the output dominate.

OK I see where I got it wrong... looks like I read Tekwiiki a bit too fast... my bad. It doesn't say the plate resistor was 50ohms, they say the plate "load" is 50ohms... I am OK with that for sure. It's 4AM here and the brain is half fucked by now, sorry. 

But they still have it wrong on output impedance value, it's not 50 it's 52...

OK I guess I should go to bed...sorry for the trouble... 

[Kosmic]

I found this sad little guy on Ebay. It was listed as a Wiltron SG-1206 (a special military version?) but it's actually really just a standard 6647B (10MHz to 20GHz) sweeper. The seller was asking 30$ and listed as "For parts or not working". And this time the listing was accurate



First, there's a big red sticker on the side saying it blows fuse (one of the fuse is effectively blown).


And, it's missing all the boards inside (Yig driver, frequency control, etc etc ...)


So there's no point trying to power it up. BUT, in the listing pictures I noticed the RF desk seemed to be intact and unopened.

And .. bingo I was right 




Got 3 Yig, a 20Ghz switch, a downconverter, 20GHz directional coupler and 70Db step attenuator. Not bad for 30$

In the end it's a bit sad the seller decided to sell the instrument in parts. If the problem is really a shorted diode, someone could have fixed it easily 

[johnh]

I see yours has a blue CRT... AGAIN ! You appear to have a talent to find these rare beauties...

That's not a blue CRT. It's a blue filter. I've since taken that filter and put it on the Type 547. I wish I could find another one. Plenty of grey and green filters but blue ones are rare.

So is this blue filter of any use to you?

It came from old tek camera

[Kosmic]

In the end it's a bit sad the seller decided to sell the instrument in parts. If the problem is really a shorted diode, someone could have fixed it easily 

Yep, one of the diode on the main bridge rectifier died and the 2 NTC didn't really liked that.





As for the RF desk, it's pretty neat, it come out of the instrument as a whole. Now finding the mission boards is pretty much mission impossible and would be way too expensive anyway. I'm wondering If I could replace all that by my own circuit, maybe add a PLL and I would have a pretty nice 10MHz to 20Ghz frequency generator. Put that in a new box with a nice screen ... hmmm

[med6753]

I see yours has a blue CRT... AGAIN ! You appear to have a talent to find these rare beauties...

That's not a blue CRT. It's a blue filter. I've since taken that filter and put it on the Type 547. I wish I could find another one. Plenty of grey and green filters but blue ones are rare.

So is this blue filter of any use to you?

It came from old tek camera

Appreciate the thought but that's way too dark. Think Papa Smurf blue. 

[cyclin_al]

Had a Hazet 1/2" drive socket set for nigh on 40 years until it got badly annealed in a workshop fire. 
Bloody good stuff !

Stahlwille rings are good stuff too and open enders nice and slim but a little weak for heavy stuff.
Look at Dowidat too.....beautifully fine rings for tight spaces.

I'm not sure I agree with the need for power driven stuff for things like wheel nuts, though.

I've almost always found that my relatively puny "upper body strength" is enough, aided sometimes by a length of galvanised water pipe to obtain more leverage.

On the odd occasion that it wasn't, the Spaghetti Monster has endowed me (& most everybody else) with a pair of considerably stronger appendages which can be used to supply more force.

This, of course, may be one of the reasons I now have a "pretend" left knee!

Well remember having this argument with my now dear departed pop not long after we got our first truck, a 8 stud 900/20 wheeled TK Bedford. We'd just done some tire work on it and he'd tightened the 1 5/16" wheel nuts with just a 18" 3/4" drive ratchet which he insisted would be quite tight enough rather than use bodily weight on an additional 3 ft length of heavy waterpipe.
Having done nearly a year in a logging workshop bouncing on 6 ft lengths of pipe on wheel nuts I let him have his say and do it his way due to the discussion becoming heated and left next day for a day in the truck well knowing wheel nuts would need tightening again at close of day.
Pop, can you check those wheel nuts I asked come the end of the day and buggered off and left him to it. 
Needless to say when I checked the extender pipe for the ratchet was not exactly where I'd left it previously. 

The subject never was given air again. 
Still, nearly 30 years on I still miss the old bugger. 

My issue has always been with getting wheel nuts back off afterwards.
I just switched to winter wheels on the truck.  To remove the nuts, the 1/2" drive air rattler was useless.  It did not even budge the nuts.  It takes a good heave with a 4 foot 3/4" breaker bar to loosen them off.  After that, the ratter is ideal to spin the nuts off and then back on.  Final tightening is done with a proper hand torque wrench.

In previous years, I have actually broken a 32" breaker bar with 1/2" drive.  However, I have learned cold breaker bars are prone to fracturing.  To be honest, I am not sure if the larger breaker bar or keeping breaker bars in the house contribute to no further breakages.  The obvious part is that SWMBO wants to break something when she finds breaker bars in her space (ie. anywhere inside the house) ...

1/2" breaker bars just won't cut it on truck wheel nuts. Period. You'll ring the 1/2" square off or break the yoke.

There's a few schools of thought on truck wheel nuts and studs, some just ensure everything is clean and barely lubricated more to keep them from rusting and ensuring relatively easy removal.
I rather like to see a good dose of oil or antiseize on the threads and yet others insist the tapers be lubricated too so to get max tightening torsion with minimum effort.
On high loads like rear duals on heavy trucks and the need to get things really tight I believe there is some merit in lubing tapers and threads especially for off road work where everything is placed under considerably more stress than on highway work.
For years we ground over hilly country with heavy loads and it sure tested if wheel nuts were tight enough.

I have never had any issue with lugnuts seizing.  I have never used anti-seize on the threads.  I double-checked my vehicle manuals; all have a specified dry torque.

I have had issue with lugnuts loosening and backing off; more than one vehicle.  I got my torque wrench calibrated; no adjustment was necessary.  As a result, I worked out alternate torque settings with a trusted garage; they confessed that they had seen other occurrences on those particular vehicle models.

On my car I used a bit of nickel anti-seize on the threads and tapers. Mainly to help prevent them scratching and galling the mating tapers on my $4000 rims.
The McGuard/TRD nuts I used have a cool feature where they have a 'floating' taper that can rotate on the nut, to further help prevent scratching and galling.

The tapers is where I do something a bit different.  I keep a piece of very fine steel wool in my automotive toolbox.  I use that to clean off the surface of the tapers on both the nut and the rim.  that gets rid of dirt and light surface rust.  As others have said, cleanliness gets the correct friction when tightening based on torque settings.

I have had a truck that had a flat surface instead of a taper.  However, the lugnut had an integrated washer.  There was a specific instruction to lubricate the washer-nut surface, but to ensure the washer-rim surface was clean.

There are those who claim that putting anti-seize on wheel studs prevents you from properly torquing the lug nuts and they will essentially be under torqued. But I've done it for years and never had an issue. Turns out the mechanic I deal with does the same.

Around here, all the mechanics say to not use anti-seize at all.  There might be something official about it, although I could not find it at the moment.

Take that with a grain of salt.     Actually, make that a tonne.  NaCl and Calcium salts are used extensively on the roads.  Nasty practice that; it really only works for ice.  However, with a lot of snow, the salt gets overwhelmed and the situation would actually be better without the salt.  The salt is also terrible from an environmental perspective, at least in the massive quantities used around here.  I tend to keep my vehicles for a long time, because the vehicle is in good shape either from not a lot of use (the truck) or the depreciation on paper does not match the actual condition (high mileage on a new car), which leads a fight against rust.  I end up using a yearly rustproofing, which is a gooey oil & wax concoction.

Regardless, there is one place around the wheel where I do use anti-seize.  I have had the experience where the wheel rim has seized onto the disc/drum/mounting plate.
After witnessing unsavoury mechanics using prybars and 8-lb sledgehammers to dislodge the rim, my imagination goes to bent brake disks and damaged rims.
I certainly do not want that, nor do I want to be stuck on the side of the road at some time.  I have been using a silver anti-seize in a very thin layer on the disc/drum/mounting plate where it mates with the wheel rim.  Since doing that, the most force needed to remove a wheel is a swift kick of the tire or tyre (in my collection, some are marked on the sidewalls as tyres and others marked as tires).

I catch up sometimes.

There, I think I just caught up ... momentarily...

[vk6zgo]

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it a " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Back in the day, the "official " impedance for coax of that type was 52 ohms.
Over time, it became "normalised" to 50 ohms, which is amusing, as 52 ohms was, itself, a "normalisation" of 51.5 ohms.

Marconi, in the UK, still used 51.5 ohms as their standard.

Thus, it came to pass, that the twin 10kW TV "Vision" transmitters (& their associated "Sound" Tx) installed around 1959 at ABW2 were to that standard.

TV transmitters of that era "grid modulated" the final RF PA stage, producing a "double sideband, full carrier " (AM) signal.

The standard was "Vestigial sideband" (VSB), so most of the lower sideband had to be suppressed.

Much of this could be achieved with the PA tuning, but to get  the result "in spec", an RF filter was needed ---A bloody big one!

To this end, "filterplexers" were used, which, in addition to filtering the LSB, also were used to combine the Sound & Vision RF signals.
The resultant signals were then fed to a "combining unit", so two of these transmitter combinations could in their turn, be combined to send 20kW of Vision & 4kW of Sound signals "up the spout".

All of this stuff required a lot of "plumbing", consisting of  coax made up of large diameter aluminium tubing, with smaller dia copper tubing suspended inside it by Teflon spacers----all 51.5 ohm!

The 1970s rolled around, & the decision was made to modify the existing transmission equipment for PAL colour, so along with a lot of other stuff, they also decided to replace the "filterplexers", combining units & associated plumbing with new units which could better meet the tightened specs required.

All good, but the new stuff, supplied by AWA, was all for 50 ohms!

The transmitters, the coax up to the antennas, & various other bits were not going to be changed, staying at 51.5 ohms, so AWA supplied "at considerable expense" a bunch of 1/4 wavelength "matching sections" of 50.7445 ohms!

These were provided, by the simple expedient of turning down the centre conductor of normal 50 ohm coax to a smaller diameter.
"A nice little earner" for AWA, but I bet the machinist didn't get a bonus for his contribution!

[Andrew_Debbie]

I picked a up 2101 at the local Hamfest a couple weeks ago. Haven't had time to do anything with it yet.

Operation and service manuals are available here.

http://www.ko4bb.com/getsimple/index.php?id=manuals&dir=Racal/Racal_Dana_2101

Reading it now.   

[Robert763]

In the end it's a bit sad the seller decided to sell the instrument in parts. If the problem is really a shorted diode, someone could have fixed it easily 

Yep, one of the diode on the main bridge rectifier died and the 2 NTC didn't really liked that.





As for the RF desk, it's pretty neat, it come out of the instrument as a whole. Now finding the mission boards is pretty much mission impossible and would be way too expensive anyway. I'm wondering If I could replace all that by my own circuit, maybe add a PLL and I would have a pretty nice 10MHz to 20Ghz frequency generator. Put that in a new box with a nice screen ... hmmm

To drive the YIG oscillators you just need the "bias" (oscillator) and heater supplies and a current source for the main coil. They are stable enough that they do not need a PLL. The current /frequency relationship is linear enough that you can use a voltage to current converter (op-amp transimpedance amplifier) with a 10 tuen pot and voltmeter scalled in frequency as a good indication. The V to I will allow sweeping with a function generator.
There is a fair bit of info on the internet.

[srb1954]

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Early versions of BNC connectors were 52 rather than the now standard 50 . There was 52 coax cable to match.

Worse : Tekwiki goes on to give an explanation of why it's 50 ohms (when it's not), it goes : " It's 50 ohms because the plate load resistor of the output/driver tube is 50 ohms ".   

Eh ?!  As you can see in the schematic, the plate resistor for the output tube is hardly 50ohms, far from that, it's 100+ times more, it's 5.6K !!

The Tekwiki description is inaccurate. The effective output impedance is actually the parallel combination of the 5k6 plate resistor and the 100 and 110 resistors on the output. This calculates out to 51.9 , near enough to the specified 52 .

[Andrew_Debbie]

Thinking about bidding on this Racal-Dana 2101 counter --> https://www.ebay.com/itm/224710802719?

Only Option 04C which is the base 'just a crystal'  frequency standard.   Missing an important button.    Manual is hard to find.

Will go for a stupid high price?


also watching this one --> https://www.ebay.co.uk/itm/284553818401

If you do: same buttons as the 1991 and 1998. I can set you up with a spare.

I may take you up on that.   

I put bids into Gixen for the 2101,  this 1991 --> https://www.ebay.co.uk/itm/353783914070   and a 9906 https://www.ebay.co.uk/itm/284553818401


The 2101 is broken.  Both are Option 04C, which is the base room temperature crystal standard.    The 9906 only has a photo of the front panel.  I am assuming it is 04C.  It still has the case which gives me hope it is in better than average condition.


I would not expect any of these to go for stupid money, but who knows.   The 1991 has 65 watchers.

[Ice-Tea]

The description of the 1991 is wrong. That's a 160MHz machine.

Also: if you want a 1991, you might be better off contacting a certain Tea guzzling forum member.

[Vince]

The first thing that boggled my mind is that the face plate says the output is 52 ohms ?! Yes 52 not 50 !  So you need 52ohms coaxial cables and plug that into a 52 ohm load/scope, if that even exists ?! I guess there must exist 52/50 ohms adapters ?!  Still, why not make the oput 50ohms to begin with ?! how pervert is it to make a 52 ohms output ?!    WHY ?! 

Is it a " thing " to be 52 ohms in the test and measurements arena maybe, at that time anyway ? What's so special about 52 ohms that you can't do with traditional 50 ohms ? I am genuinely curious, I am sure I will learn something...

Back in the day, the "official " impedance for coax of that type was 52 ohms.
Over time, it became "normalised" to 50 ohms, which is amusing, as 52 ohms was, itself, a "normalisation" of 51.5 ohms.
Marconi, in the UK, still used 51.5 ohms as their standard.

Oh, OK.... so manufacturers took their time in the early days, to converge all to 50ohms...
Since we are alwyas told that teh world / signal integrity will collapse if the impedance is not match throughout... output, in put, cables, connectors.... I guess back there was also, just might, partially.... some incentive for manufacturers to have their own particular value of " 50 " ohms, to motivate customers to buy not one piece of gear from them.... but all of it, and charge through the roof for it. Kinda the Apple ecosystem with proprietary everything.

So basically non-50ohms stuff is normally only Vintage gear then... so it should be kept in mind if one is being vry critical about signal shape/integrity.... that maybe the distortion of his signal is nothing to do with the vintage signal generator say, nor the scope he is looking at it with.. but simply a slight impedance mismatch ! IOW.... guy needs to know what he is doing, shocking ! 

[Andrew_Debbie]

Missed the 9906 -- Seller accepted an offer at the opening bid price. 

[Andrew_Debbie]

The description of the 1991 is wrong. That's a 160MHz machine.

Also: if you want a 1991, you might be better off contacting a certain Tea guzzling forum member.

I spotted the incorrect description.   Still recovering from not getting the 9906 --  Yes it is "only" 8 digits but it is 200MHz and  simpler.


If there is someone here willing to part with a 1991 for a low price.....