Russian RPN calculator series Elektronika MK

[Karl-Ludwig Butte]

Dear all,

every now and then russian RPN calculators from the MK series made by Elektronika (like e.g. the MK-61) are mentioned here in this forum. A quick search on TAS reveals that most of the offers are coming from east european countries like Ukraine, and Belarus or the Russian Federation. Prices are moderate but shipping costs are often nearly as high as the unit price.

Does anybody here in the forum has any experiences in buying such devices via TAS from these countries of origin? Are the sellers trustworthy and reliable? And what about customs? Or would you recommend to wait for an offer that would be shipped from ones home country even if it is more expansive?

Last but not least what do you think how important are Elektronika RPN calculators for any serious calculator collection?

Thank you very much for your feedback in advance

Best regards

Karl

[toml_12953]

(05-22-2019 01:27 PM)Karl-Ludwig Butte Wrote:  Dear all,

every now and then russian RPN calculators from the MK series made by Elektronika (like e.g. the MK-61) are mentioned here in this forum. A quick search on TAS reveals that most of the offers are coming from east european countries like Ukraine, and Belarus or the Russian Federation. Prices are moderate but shipping costs are often nearly as high as the unit price.

Does anybody here in the forum has any experiences in buying such devices via TAS from these countries of origin? Are the sellers trustworthy and reliable? And what about customs? Or would you recommend to wait for an offer that would be shipped from ones home country even if it is more expansive?

Last but not least what do you think how important are Elektronika RPN calculators for any serious calculator collection?

Thank you very much for your feedback in advance

Best regards

Karl

I bought one from Bulgaria. It was shipped quickly and was described as being NOS. When I got it, it didn't have the removable protective plastic film that was supposed to be covering the display so I have doubts that it wasn't used instead of NOS. Oh well, still it was cheap and included everything shown in the photo so I was pleased anyway.

[burkhard]

(05-22-2019 01:27 PM)Karl-Ludwig Butte Wrote:  Does anybody here in the forum has any experiences in buying such devices via TAS from these countries of origin? Are the sellers trustworthy and reliable? And what about customs? Or would you recommend to wait for an offer that would be shipped from ones home country even if it is more expansive?

Last but not least what do you think how important are Elektronika RPN calculators for any serious calculator collection?

I bought one (MK52) out of Ukraine and it came in the condition promised (mint) and worked fine. The price a year ago was $35 + $20 shipping which I considered OK. I would not pay extra to get one shipped from a domestic source. These things are not very rare or expensive, so the risk is not so great anyhow. Most of the sellers sell a LOT of stuff on the auction site, so I suspect they value keeping a good reputation, just like they would anywhere.

I'm in the USA and I never seem to get charged duty for any of the overseas stuff I buy off TAS, and that has been a bunch over the years. The US customs people it seems do not concern themselves with such "little stuff".

Regular AA batteries fit the MK52 *very* tightly... stresses things more than I would like. The flat-top ones, being a little shorter, are better. I would recommend these.

These things are not up to the build quality of old HP calculators by any means, but for a serious (or even casual like me) collector are a nice piece of history and great conversation piece for the office desk. I think they are a good value.

[jebem]

I am based in Europe and have been ordering calculators, radios, and electronic components on eBay from the eastern European countries like Bulgaria, Ukraine, Russia among others and never got issues with them.

Delivery time is fair and shipping is kind of cheap when compared to what some western countries ask.

The mk calculators prices seems to be increasing year after year but we can still find good items at a fair price.

New old stock from these countries is not what western people expect. I guess they do not store or handle these goods in the best way, considering the temperature extremes they have there. The mk models are not that old, many were manufactured in the 90's, but when you look to them it seems like 40 years have passed over them.

The most weak feafure imho is the keyboard key's travel that is close to zero. Casio have super keyboards when compared to MK machines. However they register the key entries most of the times, and if that is not acceptable, it is possible to open the machine and repair the keyboard. A good cleaning and a new foam will usually help.

Still they are a good way to spend a few Euros and have a piece of history preserved for future generations.
Oh, and it is still possible to buy the vfd displays (really new stock) for these machines as well.

[Maximilian Hohmann]

Hello!

(05-22-2019 01:27 PM)Karl-Ludwig Butte Wrote:  Does anybody here in the forum has any experiences in buying such devices via TAS from these countries of origin?

Over the years I have bought quite a few things from former Eastern Block countries (not only calculators). All via eBay and paid through PayPal. One parcel I got from Chișinău in Moldova which is so rare that I kept the box because it has so many exotic stamps on it.

Ukraine is usually quite fast, about one week delivery time. The shipping cost can actually be quite low, watch out for that. The last thing I got from the Ukraine a few weeks ago is a wifi adapter for my telescope drive (which cost 1/4 of the original part) and that came with free shipping (and no import duty either). Some sellers want to make extra money by quoting ridiculous shipping charges, but this is common practice in other countries as well.

Regards
Max

[Karl-Ludwig Butte]

Dear All,

thank you all for your detailed answers with your experiences and appraisements. I guess I'll try to expand my collection and add some of the russian models to my collection.

Best regards

Karl

[burkhard]

(05-22-2019 07:04 PM)jebem Wrote:  New old stock from these countries is not what western people expect. I guess they do not store or handle these goods in the best way, considering the temperature extremes they have there. The mk models are not that old, many were manufactured in the 90's, but when you look to them it seems like 40 years have passed over them.

Yes, I've also seen this on varied N.O.S. stuff I have bought out of former Soviet-bloc countries. I am pretty sure the item itself is new, but the original boxes (low quality to start with) are usually stained and falling apart, their seam glue deteriorated. I suspect storage is frequently in unheated sheds or warehouses with perhaps a bit of dust / moisture getting in over the years. So, just keep this in mind... probably not indicative of a poor seller, just the way things are. My calculator (and the other stuff as well) itself works very nicely.

[rprosperi]

FYI - Here's an MK-61 just listed; price is $25 and shipping only $15, coming from Ukraine. But it is not risk-free; although it looks virtually new, seller does not know if it's in working condition:

https://www.ebay.com/itm/Mint-Soviet-RPN...3527796511

[Karl-Ludwig Butte]

(05-23-2019 10:15 PM)rprosperi Wrote:  FYI - Here's an MK-61 just listed; price is $25 and shipping only $15, coming from Ukraine. But it is not risk-free; although it looks virtually new, seller does not know if it's in working condition:

https://www.ebay.com/itm/Mint-Soviet-RPN...3527796511

Thank you for your reply. I doubt that this is an unused unit. I compared it to the one I got from a colleague, who is from Hungary. The right switch of the offered unit is white and looks different compared to the left one which is black. In my unit both are black and from the same type. Or could it be that Elektronika used different switches in production when supplies of one type where not available?

Best regards

Karl

[toml_12953]

(05-24-2019 06:56 AM)Karl-Ludwig Butte Wrote:  Or could it be that Elektronika used different switches in production when supplies of one type where not available?

That is most likely the case. Commodore used to do the same thing with the PET. I bought two chiclet keyboard PETs hoping to cannibalize one to fix the other. There were few parts I could use. Even the keyboard connector was different! In Eastern Europe the parts situation was even worse than for Commodore.

[toml_12953]

(05-22-2019 01:27 PM)Karl-Ludwig Butte Wrote:  every now and then russian RPN calculators from the MK series made by Elektronika (like e.g. the MK-61) are mentioned here in this forum. A quick search on TAS reveals that most of the offers are coming from east european countries like Ukraine, and Belarus or the Russian Federation. Prices are moderate but shipping costs are often nearly as high as the unit price.

If your Russian is as good as your English then you won't need this but if your Russian could stand improving then here's an English translation of the manual for you:

https://www.dropbox.com/s/ztp6t51td3rapb...h.pdf?dl=0

This is the latest version I could find. If anyone has a better translation, then please let us know!

[Karl-Ludwig Butte]

Hi Tom,

thanks for your replies. I had found this translation, too. And thanks a lot to Jebem for that incredible work! Otherwise I had a lot of difficulties finding out how to work with the MK-61.

Best regards

Karl

[burkhard]

(05-24-2019 04:19 PM)toml_12953 Wrote:  If your Russian is as good as your English then you won't need this but if your Russian could stand improving then here's an English translation of the manual for you:

https://www.dropbox.com/s/ztp6t51td3rapb...h.pdf?dl=0

This is the latest version I could find. If anyone has a better translation, then please let us know!

Does anyone have something similar for the MK-52? I imagine it is similar, but if there's a specific translation of that manual available, all the better.

[Eddie W. Shore]

(05-22-2019 05:40 PM)burkhard Wrote:  

(05-22-2019 01:27 PM)Karl-Ludwig Butte Wrote:  Does anybody here in the forum has any experiences in buying such devices via TAS from these countries of origin? Are the sellers trustworthy and reliable? And what about customs? Or would you recommend to wait for an offer that would be shipped from ones home country even if it is more expansive?

Last but not least what do you think how important are Elektronika RPN calculators for any serious calculator collection?

I bought one (MK52) out of Ukraine and it came in the condition promised (mint) and worked fine. The price a year ago was $35 + $20 shipping which I considered OK. I would not pay extra to get one shipped from a domestic source. These things are not very rare or expensive, so the risk is not so great anyhow. Most of the sellers sell a LOT of stuff on the auction site, so I suspect they value keeping a good reputation, just like they would anywhere.

I'm in the USA and I never seem to get charged duty for any of the overseas stuff I buy off TAS, and that has been a bunch over the years. The US customs people it seems do not concern themselves with such "little stuff".

Regular AA batteries fit the MK52 *very* tightly... stresses things more than I would like. The flat-top ones, being a little shorter, are better. I would recommend these.

These things are not up to the build quality of old HP calculators by any means, but for a serious (or even casual like me) collector are a nice piece of history and great conversation piece for the office desk. I think they are a good value.

I agree regarding the batteries, the fit isn't very good. I don't where I could find the flat-top batteries.

[burkhard]

(05-28-2019 04:28 PM)Eddie W. Shore Wrote:  I agree regarding the batteries, the fit isn't very good. I don't where I could find the flat-top batteries.

Put flat top AA (no quotes) into the search bar of your favorite auction site and you will see a bunch of lime green generic NiMH rechargeable ones up for sale. They cost about $US10-$US11 for a set of 4 with free shipping in USA. They still are a smidge tight IMO, but much better than normal ones.

[toml_12953]

(05-28-2019 06:15 PM)burkhard Wrote:  

(05-28-2019 04:28 PM)Eddie W. Shore Wrote:  I agree regarding the batteries, the fit isn't very good. I don't where I could find the flat-top batteries.

Put flat top AA (no quotes) into the search bar of your favorite auction site and you will see a bunch of lime green generic NiMH rechargeable ones up for sale. They cost about $US10-$US11 for a set of 4 with free shipping in USA. They still are a smidge tight IMO, but much better than normal ones.

Have you used them for any length of time? The manual specifically warns against using rechargeable batteries.

[burkhard]

(05-29-2019 02:49 AM)toml_12953 Wrote:  

(05-28-2019 06:15 PM)burkhard Wrote:  Put flat top AA (no quotes) into the search bar of your favorite auction site and you will see a bunch of lime green generic NiMH rechargeable ones up for sale. They cost about $US10-$US11 for a set of 4 with free shipping in USA. They still are a smidge tight IMO, but much better than normal ones.

Have you used them for any length of time? The manual specifically warns against using rechargeable batteries.

No, I have not. I wonder what the concern is? Maybe Soviet-era rechargeable batteries are a little sketchy in terms of leakage? Or maybe the nominal voltage of the rechargeables is a little low for the DC-DC converter needed to drive the VFD?

I haven't used the calculator extensively, but it did work and I didn't notice any trouble.
Perhaps I need to exercise it a bit more!

[toml_12953]

(05-29-2019 03:10 PM)burkhard Wrote:  

(05-29-2019 02:49 AM)toml_12953 Wrote:  Have you used them for any length of time? The manual specifically warns against using rechargeable batteries.

No, I have not. I wonder what the concern is? Maybe Soviet-era rechargeable batteries are a little sketchy in terms of leakage? Or maybe the nominal voltage of the rechargeables is a little low for the DC-DC converter needed to drive the VFD?

I haven't used the calculator extensively, but it did work and I didn't notice any trouble.
Perhaps I need to exercise it a bit more!

If it's built anything like Russian farm equipment (Formerly Belarus - now MTZ) you'd need a bazooka and maybe some small-scale nukes to hurt it.

[John Keith]

(05-29-2019 02:49 AM)toml_12953 Wrote:  ... The manual specifically warns against using rechargeable batteries.

NiMH cells are lower in voltage than alkaline cells so it is very unlikely that they will damage the calculator. The worst that can happen would be erratic operation, dim display etc.

[jebem]

(05-29-2019 05:03 PM)John Keith Wrote:  

(05-29-2019 02:49 AM)toml_12953 Wrote:  ... The manual specifically warns against using rechargeable batteries.

NiMH cells are lower in voltage than alkaline cells so it is very unlikely that they will damage the calculator. The worst that can happen would be erratic operation, dim display etc.

Surely the machine switching regulated power supply can cope with a large input voltage variation, as long as it is in good shape (electrolytic caps failure rate is high here).

Also the lower internal impedance of modern rechargeable cells compensates for its lower nominal voltage supply, when compared to 1.5V non-rechargeable cells, specially for the lower quality ones, that will have a higher voltage drop when supplying 100 to 200mA consumed by these calculators.

The calculator was designed to work with 4.5V nominal input voltage, coming from one of two power sources:
1. Three 1.5V non-rechargeable cells (little smaller than standard AA batteries) commonly found in the Eastern Countries in the USSR era, to give the machine portability while traveling around;
2. An alternative Elektronika D2-10m AC kind of regulated power adapter to use as a desktop machine. In this case the batteries should be removed.

Probably people would think that the power adapter was a charger but that is not the case.
Hence the note in the documentation.
Just my 2 cents of Euro.