Kantronics KPC-3 (non plus)

Quick guide to Upgrade your KPC-3 (non plus) and other obsolete Kantronics TNC’sWell if you found this by searching the internet you are probably wanting to know how to upgrade your old KPC-3 (non plus) TNC to the latest 8.2 firmware. Well Kantronics no longer supports this great TNC. That is rather irritating to me so I went on a mission to solve this problem. Well fret not……You can buy an inexpensive EPROM chip and a programmer and fix your own TNC. Once upgraded the TNC works great on APRS.
IMPORTANT – Write down all your TNC settings. The following process will erase all your TNC settings such as your call sign, settings, and any mail you have saved in your mailbox. Save it, write it down, do something.

Take the little screws out that hold the top cover on the TNC. Once the cover is off, one of the bigger chips inside the TNC will have a white sticker on it that states the “KPC-3” and the firmware version. This is the chip you will replace so make sure you put the new one in the same way the old one is. You will see a little notch on one end of the chip (see below). Make a mental note on the chips orientation.

Above is a KPC-3 (non plus) with a v5.1 firmware chip.

Above is a KPC-3 (non plus) with a v6.0 firmware chip.

I took my version 5.0 firmware chip out of my TNC and pulled the sticker off. It’s a very common M27C512 EPROM chip. They cost about $5 and you can buy one from many online stores such as:
The chips come in many speeds but my original chip is a 200ns.  You can buy anything faster than 200ns and it should work fine (example 150ns, 120ns, 100ns, etc.)  Avoid the slower chips like 250ns.  They might not work.
You do not have to pull your sticker off just leave it on. I removed mine to identify the chip.

Here are two chips I purchased online. They are the same and you only need one. It is possible to erase your original chip by exposing it under strong UV light however I discourage this. I would keep your old firmware chip in a safe place in case you mess up.
Now you need an EPROM programmer. I bought a cheap Willem EPROM programmer off Ebay for about $30. There are many cheap programmers that will work just make sure it supports the 27C512 series EPROM chips. Do a search on google or ebay to find one.

The programmers come with easy to use software and support USB or the printer parallel port. Mine even came with a cable.
All you have to do it plug the new M27C512 chip into the programmer as per your instruction manual, run the software that came with the programmer, and finally load the 8.2 Firmware file. Press the “Write” button and wait a few minutes while the new firmware chips is being written. Its just like burning a CD on your computer.
When its done, you can reinstall the new firmware chip into the TNC and turn it on. All your original TNC settings will be erased and you will have to reprogram your call sign and settings back into your TNC.
Thats it.
Download the Firmware below:
KPC-3 (non plus)  5.0 Firmware
KPC-3 (non plus) 5.1 Firmware
KPC-3 (non plus) 6.0 Firmware
KPC-3 (non plus) 6.0N (K-Net 1995) Firmware
KPC-3 (non plus) 6.0N (K-Net 1996) Firmware
KPC-3 (non plus)  8.2 Firmware
KPC-3 (non plus) Manual
KPC-3 v8.2 Rom Manual Addendum
Good luck.

Firmware for other Kantronics TNC’s:

KPC-9612 (non plus)  v6.0 Firmware

KPC-9612 (non plus) v7.0 Firmware

KPC-9612 (non plus) v8.2 Firmware

KAM v5.0 Firmware

KAM v6.1 Firmware

KAM+ v8.0 Firmware

KAM+ v8.2 Firmware

KAM+ All Firmware, Schematic,  & Parts List

KPC-2 v5.02 Firmware ,  Schematic,  & Parts List

KPC-4 v5.01 Firmware,  Schematic, & Parts List

Excellent old packet TNC software PaKet v6.2


  1. Thanks for this great KPC-3 page. I just purchased one, with the 6.0 software and now can upgrade it to the 8.2 software. Many thanks for your support of this great TNC.

  2. I am looking for someone who is willing to burn a rom or two with the 8.2 software on them… I can pay for your time. Could you help me out?
    I have a TNC with the 5.0 software that I can send back to you if you want it after the upgrade.

  3. Pulled my KPC-3 (non-plus) out of storage, was wanting to use it on APRS. Found your site, followed your suggestions and was able to successfully upgrade v8.2. Thanks for the support and keeping these older units on the air!

  4. I haven’t used my KPC-3 v5.1 in a long time due to lack of activity in my area. I would like to sell it but a new version of the firmware would a be better deal for the buyer. I have seen several versions of the eprom of varying speeds, I have no idea of the appropriate chip.
    I don’t have a programmer either and I expect that buying one would lose for a one shot deal. I would certainly be willing to pay a reasonable fee plus shipping if you could do this for me. If not, thanks for your work anyway!

  5. Thanks, we upgraded v6.0 to v8.2 to get an APRS digipeater working. v8.2 has that bug which requires the UIDigi setting to include WIDE1-1. Do you know if there was ever a v8.3 firmware for the non-plus to fix that?
    Also, I can burn EPROMs for any VK stations that needs it done. Their freight cost of course. Email my callsign at gmail

  6. HI MIke, Thanks for the great info on the kpc3…I found one buried in my junk pile…going to buy a burner and flash a new rom as soon as it comes from mouser! Any idea of anyone having firmware upgrade bin files for the Kantronics KAM? I’ve got the old original KAM but cant find squat on it!!!!
    Tnx es 73
    Lyndel, N7LT

  7. hello good afternoon, sorry for a question, I arrived a few days ago they sent a EPROMs do with the version 8.2 for kpc3, and kpc9612 kam plus, but by placing it in my kam plus, they stay lit all the LEDs of tnc, not if have to be some adjustment or move any jumper to work the EPROM (27C1001), as with the others who recorded (27C512) are running the kpc3.
    Such action we are doing here in Mexico, to build and strengthen the national network of aprs. Thanks for your support, I am of you for any information. 73.

  8. Would you be interested in more KPC eprom images? I have the V5 for the KPC2, V6 for KPC3 (non plus), and V9.1 for KPC9612 Plus. let me know.

  9. I have almost all the newer images for KPC-3 plus and non-plus, KAM and KPC-9612 plus and non-plus.
    I use a Willems 4.1 EPROM programmer.

  10. I’d also like copies of the v9.1 images for KPC-3+ and KPC-9612+ if possible. I also have a KAM with Enhancement board and v8.0 software that needs update to v8.2 if anyone has that image. Please email to dhreed (at) q dot com.
    If anyone doesn’t know what firmware versions they need, you can look at the two links above. The Legacy link is for the old products, the second link is for current products. Remember that both the model number and the firmware version must match before you can use the new EPROM in your old equipment.
    Thank you for having a most informative site!
    73, Doug.

  11. Hi Mike,
    I could use a quick hand debugging. I got the burner and chips as you suggested, toasted the first one, but that is my normal mode, so I bought spares… 😉 loaded both 6.0 and 8.2 (non-plus) on their respective chips. 8.2 does not even power up, no green light. 6.0 however flashes the power LED. any ideas as to what happened?
    \73, Per

  12. The majority of email clients (and I’m talking close to all of them) will not accept flash or other executable files because of the risk of viruses. In fact, many Anti-Virus applications simply strip the code out and leave you with a blank box instead — which is probably what you’re seeing, and why your code is working in Word, but not when you send it through an email. . . You can try to ‘trick’ it by sending the call through an Iframe command instead, but most email clients will also not accept iframe commands because of this same danger. . . This holds true for almost all the major email clients — Outlook, Outlook Express, Eudora, Thunderbird, etc… as well as MacMail, AOL and Webmail based clients such as Yahoo, Hotmail and Gmail… . . Bottom line — don’t use Flash in your email. . . Sorry!

  13. Thanks for all the GREAT info! Im going to get a programmer and do my own KPC3 upgrade..(at least thast the plan now!) Does anyone have the latest firmware for the KAM allmode?

  14. Thanks for the info!
    Please forgive my ignorance, but I am curious to know if the TNC with the old firmware can still be used in an APRS mobile tracker set up? Or will older versions not support the APRS protocol?

  15. Mike, I just ran across your site. Thank you for the information and support for the KPC3. I have one of these units and ran 1200 baud packet for years, but I was ready to put it in the outdated pile because there was no APRS functionality. Two years ago, I purchased what I thought was a new 8.2 chip for the KPC3, but was bummed out when it arrived and was for the Plus.
    Time to order a new blank chip and eprom burner.

  16. Mike.. Thank you So Much ! A great getting started tutorial,
    I bought the programmer and some eproms for my Kam Plus and my Kam 9612.. Both are up to 8.2 with the very first burns..
    You made this look so easy and it was. Thanks Again..
    Tom KN6PJ

  17. Got the chip and the Willem pro burner. I attempted to burn the Chip, and at first all seemed ok (KPC 3 Ver. 8.2 reported). However, when I perform a hard reset on the KPC3, I am getting a Check Sum error. When I attempt to enter my call it reports “Erro”. Anyone else run into this problem? Maybe there are other settings for the Willem programmer I need to adjust, besides the obvious (jumpers, voltage, etc). There are a bunch, but I am just not that familar with programming eproms. When I reinstalled my 5.1 chip, the Check Sum error disappeared.
    Thanks for any advice.

  18. I gave it another shot this evening, worked fine this time. Unsure of what happened the first time. Nevertheless, I am a happy camper now.

  19. Ok making progress, my kpc9612 version 7 chip from kantronics has more pins than the earlier 5.2 kantronics 9612 chip. The latter is the same size as my 27c512. Anyone know where it fits in the socket – sounds a daft question but its not obvious.

  20. All sorted.
    1. The smaller 27c512 chip is ok in the larger firmware socket of the kpc9612. It goes furthest right from the battery.
    2. Remember to programme the Willem at 32 bits crc. (not 16 bits).
    Hope that helps someone.

  21. Mike, are you still able to program the 27c512 eprom’s for the KPC-3. I am thinking of turning mine into a digipeater for our local club, unfortunately no eprom programmer locally……
    Paul KF4DJQ

  22. Mike
    Great site great info !! Looking for some one to burn the 8.2 fw do you offer this — no money to spend on the burner can you reflash the original 6.0 chip I have

  23. Thanks for all the help. Upgraded the KPC 3 V5.0 to 8.2 with the Willem burner that came today. Have 3 Kam Plus to do when the right chips arrive. I saw a post about 32 bit crc for the 9612. What is this about? I just took the default on the KPC3

  24. Help. I tried to program a 27C512 with Ver 8.2 for the KPC-9612 (non-plus) and when I swap the ROM the power light blinks on and off and no response to the serial port. Tried at 16 ADD and 32 CRC with no luck on either. What am I doing wrong? The programming for the KPC-3 went OK.
    I noticed the 9612 power light will not turn on without the ROM chip inserted. Could I have the wrong 27c512? The factory one is a M27c512-15 and the ones I have tried are M27c512-12

  25. I have the same problem as Dave Christensen with a KPC-9612. Power light just flashes on/off. Mine is an early model (late ’94 or early ’95) that shipped with 5.2. Perhaps there were hardware changes between then and when 8.2 was shipping?

  26. I think I know what the problem is with the KPC-9612 firmware. If you look at the binary file sizes, the KPC-3 files are all 64KB while the KPC-9612 files are 128KB. You can’t write a 128KB file to a 27C512 since it only holds 64KB. You’d need a 27C1000 (128KB) to write these .bin files. I’m going to give a 27C1000 a try early next week and will report back if it works.

  27. Try as I could I couldn’t fit a 128k image for my KPC-9612 into a 64k eprom. Got the right chip (27c010) and I have version 8.2 working.
    Anybody have a V8.2 image for the Kam Plus? I have three of these I would like to get upgraded. I have a co worker that has 2 Kam Plus units he has shelved. He would love to get them running newer code.
    Thanks for the great website, examples, and user comments. I have really enjoyed it.

  28. By the way, the 1Mbit chips like the 27C1001, 27C010 and the 28F010 are old and pretty much special order only at the major chip sources but eBay has bunches of them pretty cheap.

  29. Just blew the dust off my KPC-3 this week and tried to connect to it, seems the firmware (ver 5.0)is corrupt and will not work properly. So I ordered a new 27C512 from Mouser and just programmed ver 8.2 into it and installed. Everything is working great!
    Thanks for the great info Mike, it really helped to keep this old and still great TNC working!

  30. i have looked high and low and have upgraded my kpc3 but i also have a plain KAM (no +) and looking for the 8.20 firmware for it as well. cant find anyone to clone an eeprom from or read one. If i could find the bin file at least i would be happy. Any ideas??
    thanks Andy 73’s

  31. I am helping our local club get a fill-in digipeater setup for Northwest Florida. I purchased a KPC-3 (non plus) and am going to upgrade it to ver 8.2 from your bin file. Do you know if it is the “early” or later release of 8.2 that I see a lot of references to? Thanks for providing this info! I like to save $$ and recycle good equipment as well.
    73 de Jason, N4JTC

  32. Was so pleased to find your web page. We have a lot of TNC’s that need updating here. If you can ever help with the Heathkit HK-21 / Tasco TR-21 Micro TNC’s, AEA PK-88, AEA PK-232MBX, PacComm Tiny2, MFJ 1270B/C/Turbo we are also looking for firmware updates for these. Thanks so much!
    ~Ken – vk4akp~

  33. do you have any updated firmware for the kpc tnc’s. also i used a kpc9612 v8.2 firmware download from your site and it did not work.

  34. Hi, I am working in the Colombian APRS network and here we are using DIGI_NED for the wide digis. We have some OLD KAM ALL MODE with the first firmware, so we need the Latest 6.1 (without enhancing board), anybody have or know where can we download this .bin? Please help us. Is so hard to find it at internet.
    Thanks a lot

  35. I tried all appropriate versions for my KPC-9612 (non-plus). Each one checksums ok when I set the hard reset jumper, but once I restore that jumper to disabled, the power light just flashes.
    I only have 32K of RAM so I’m thinking perhaps that’s it. Anyone have any idea what a blinking power light means?
    (Thanks again for this page.)

  36. Mike,
    What a good resource your site is for many many “Legacy Product” KANTRONICS owners!
    I have several KPC-2 & KPC-3, and a KPC-4 and KAM-98. I have been trying to locate the KPC-4 version 5.1 EPROM / firmware.
    F.Y.I.: KPC-4 Version 5.01, was an early release of, and became version 5.0 with a date code. The last released update for the KPC-4 from KANTRONICS was version 5.1 which added “smart” mailbox features, with message forwarding to & from another pbbs/bbs.

  37. Need help Burning chip’s! Purchased Willem programmer and look much different than Mike’s. Can’t seem to get Willem to work. I have a bunch of KPC-3’s and KPC-2 & KAM Plus/Allmode to upgrade! I have already purchased the new eprom for this task. TNX 73 de KA1CVv

  38. Have been trying to find eprom # for mailbox upgrade for the Kam 98 and Kam + ver 8.0 and Kam + 8.2 Would like to upgrade mailbox storage to 512k. Thanks Dan.

  39. Yes, this is indeed a great resource you have here. The reason that these old firmwares are hard to find is that no one has been willing to post them because it is illegal! What you are doing is admirable to the HAM community but it is also copyright infringement and subject to penalty under the Digital Millennium Copyright Act (DMCA). Be careful.

    • Kantronics has the right to ask me to take this down. I hope they don’t and continue to let me help support some of these older TNC’s that are still around. I do not profit from this in any way and I do not post firmware for their current line of TNC’s.

  40. Hey I also have a kantronics 9612 (NO PLUS)that I picked up at a local ham fest. When I power it up the Power Light Stays solid for a few min but then Starts Blinking. It will blink fast,slow and vary in brightness as well it will dim to the point that you almost can’t see it.
    Any Idea why it is doing this ?
    Any help would be greatly appreciated!!
    Andrew Owen

  41. It’s great what you’re doing here . I opened my KAM+ and my chip is a M27C1001-15F1 . Can’t find that chip . Would the M27C512 work in it’s place ?
    TNX de N0VVR

  42. Got my hands on a second hand KAM Plus. It took me a while to get used to it after TAPR clones and my old faithful, PK-232.
    However I got the idea how it works and gonna download
    v. 8.2 rom image, just for fun. Thank You for the job done.
    73 de OH3WE, Kai

  43. I am currently trouble shooting a KPC-3 tnc. When I power up, the sequence is difgferent with each push of the power button. Some times onlly the power light is on and other times Tx or con or both turn on. Checking pinout voltages on U1 shows about -9v where on a working kpc-3 it is a positive voltage. I am a bit rusty on logic tracing. Do yo have any suggestions?

  44. Thanks Mike for publishing this.
    I burned a new eprom for my KPC9612 (working ok with his version 5.2) using the firmware 8.2 found in this site, but when I turn on, the power led starts blinking and the tnc does nothing…Anybody else tried to update the KPC9612 (non plus)? Maybe I have to expand the RAM memory (actually 32K)? Thanks

  45. I’ve got a kpc 3 plus, with 9.1 firmware. It had extreme issues delaying the packets. Then it quick sending packets altogether. Any idea where I can get the 32 pin updated 9.1 chip?
    Thanks in advance
    Scott, KD5DFL

  46. I bought a KPC-1 with an old ROM init.
    Would love to know if you have any upgrades.
    Version 5.0 would give me software DCD.
    It, in absolute markings on the chip…………….
    Can you help me?

  47. ** Clarification **
    The KPC-9612(NON-PLUS) uses the same 27C512 EPROM as the KPC-3(NON-PLUS) in socket U19 of the KPC-9612(NON-PLUS). Just different firmware on said EPROM.

  48. KPC 9612 non-plus firmware for 7.0 and 8.2 works fine from this website, the difference is, you need to use an M27C1001 chip, the M27C512 chip does not have enough space to hold the updated firmware. I just installed 8.2 and its up and running. Its probably a good suggestion to find yourself the 512k memory upgrade chip. You can normally find these on Ebay for $25.00. Its not required, but if you are going to 8.2, might as well take it to the max. 73s

  49. Hi Mike the Willem EPROM programmer you brought from Ebay for about $30 what model it is I am seeing many models I want to buy the exact model you buy
    Thanks your work on the kam is great full support
    de Julien 9z4fz

  50. Good Day,
    Excellent website, I am heavy into packet radio and would like to find a copy of the Knet firmware which has netrom for the KPC-3 non plus. Any ideas?

  51. Great bunch of info on here, thanks for posting it. I’ve gotten myself a bunch of firmwares from various TNC’s. AEA, MFJ, PacComm, Kantronics. Only firmware I’m looking around for is something for the PK-88, if there’s anything newer than 23-Aug-91 out there. Both of mine have the same version of firmware, one is made in Hong Kong, the other in China. Guessing the China one is newer.
    73, Jay

  52. Does anyone have the 24C16 firmware. My KAM stopped responding at enter callsign after press (*) to set baud. Keeps going back to asking Baud after I turn it off and on again. Callsign sends green LED to centre after Space but that’s it, no more response. Any help is very much appreciated de M0STo Spence

  53. What version of Willem programmer are you guys using to program the kpc9612 for the 8.2 version upgrade. I have the Willem enhanced board version and its not wanting to work.

  54. The KPC-2, KPC-4, and KAM that upgrade to the latest software use the 24C16 EEPROM chip to store your operating parameters like callsign and the rest. There is no firmware in the 24C16 as such, but when you install the new chip, the first thing you MUST do is a hard reset. The hard reset will clear out the 24C16 and load the default info that is expected. After that you should be able to program and operate as usual. At least it worked for me when I upgraded a KPC-2 and KPC-4. YMMV. 73, Doug.

  55. I can confirm that you will need a 24C16 to go from 2.X to 6.1 in an original KAM. Swap it out with the 2404 and do a hard reset.

  56. Many thanks for providing the firmware upgrades. I’ve just added the RTC to my old KPC3 non-plus and want to upgrade the firmware to 8.2. My EPROM programmer is an Aval PKW1000 connected to a PC running Realterm. The PKW1000 has six transfer modes called ASCII hex space, Dump List, Fujitsu Format, Intellec Hex, Motorola S format and Tektronix hex. It doesn’t recognize the .bin files I downloaded from your site. I’ve transferred files from programmed EPROMs to the computer so I know the terminal and interface are working. When opened in a text editor, the transferred files look nothing like the .bin files.
    Please can you provide them in one of the formats listed? Otherwise, do you know of a site that will convert them? A Google search only brought up bin to ASCII converters that do one byte at a time. I can do that myself!
    Thanks in anticipation and 73,
    John G4EDX
    Nottingham, England

  57. Been looking for updated firmware for my old KPC-2 for a long time.
    I have a couple of newer usb programmers PRO-65B
    But my old mainstay is a Data IO 2900 that will do just about anything.
    I actually bought it from Tucker electronics who used to sell ham gear.
    Now to find my KPC-2

  58. I tried the KAM v6.1, into a 27c512 and it wouldn’t work, until i realised my error.
    V6.1 is 128kb, which needs a 1024mb eprom (128k x8 bits).
    64k bin files need a 512kb eprom 64k x8 bits (512kb).

  59. ALLIANCE MEMORY AS6C4008-55PCN is a good low cost fit for the KPC3/3+, 9612 etc. For a 512kb (max size) memory upgrade, I cut LK6 as per manual, but soldered a 3 way header in and use a jumper to select large small memory should i ever want to swap back.

  60. Thank you for all these useful things about the KPC-3! I found them very useful, I wonder if someone could help me in stating which kind of “chip” I could use to add a Real Time Clock to my KPC-3 , I think should be something quite common but I am not able to understand what to seek for.
    any help?
    thank you for reading
    Antonio IZ0DCK

  61. Just need some clarification I have a KAM+ with 7.1 FW I need 8.2 to make it work for an APRS digipeater? Do I need the 27C1001 IC or will the 27C512 work?
    I have the burners and everything to do it just wan to make sure I am on the right path.
    TNX Jim

  62. Hello, do you know what is the difference between kpc3 and kpc3+? I have a kwm-1200+ and for first look I say that looks like a kpc3 (non plus)

    • The KWM TNCs are the commercial version of the standard ham KPC TNC. In order to convert from KWM to KPC you need to buy a firmware update kit from Kantronics. The kit will include the latest version of KPC firmware for the TNC, and a SECOND chip which is a microprocessor that is used to translate memory addresses for KPC standard versus KWM standard. Kantronics used this memory conversion specifically to prevent easy conversion from one model to another. Commercial companies could not buy the cheaper KPC TNC and put KWM software into it without buying the upgrade kit. I purchased a KWM to KPC upgrade kit about 10 years ago directly from Kantronics and upgraded one KWM-9612+ to a KPC-9612+ at a cost of about $60. I suggest send an email to Kantronics Customer Service and explain you want to convert a KWM TNC and ask for the firmware upgrade to a KPC-9612 with the required memory address chip. Hopefully someone will know what you want and will be able to find the correct files and chips to burn. Your other option would be to find a damaged KPC of the correct model and see if the memory address chip is still good. The TNC will work fine after you install the upgrade kit. Be very sure to specify exactly what model of KWM-9612 firmware and board rev you are converting from! 73, Doug.

  63. I’m looking for K-Net firmware for non-plus versions of the KPC-3 and KPC-9612.
    Any help would be appreciated. Thanks in advance

  64. I see a upgrade 8.2 for a KAM+, what, if anything can be done to up grade a reg KAM
    Trying to reuse my old KAM ?

  65. the ram chip 6825512LP-70
    this also comes out to be another similar chip BS62LV4006 from tiawan
    has anyone tried this chip as it is also refered to as the jameco replacement
    eprom 27c512 is said to work.. some also say 27C1001 or 27C010 EPROM 200ns or faster.

  66. u 19 replacement is 628512LP-70 to make it 512k and this also comes out to.. BS62LV4006 which is what jameco says the chip is… or basicaly… kantronics says its a jameco part number… Jameco Part no.: 157358 which is Manufacturer p/n: 628512LP-70 and this comes out to…. BS62LV4006

  67. this may help people with kam plus..
    i picked up one that was 6.1 and decided to upgrade the mailbox..
    i replace U19 with an as6c4008-55pcn which is a chip i bought from a company called little diode in england.. it was sent and all for less than 10$
    i reset the device.. did the k6 jumper bridge and removal.. the device tries to autobaud by hitting ‘*’ astersk
    works fine and the chip arrived quickly.
    best wishes.. now all i need is a new eprom big mailbox is nice tho (-:

    • Mar 2022- I found an Ebay seller listing a KPC-3 v6.0 with K-net v1.0 EPROM. I haven’t received it yet so I don’t know any more than that. I also have a v5.1 EPROM that said it ran K-net, but haven’t tried it yet. I assumed K-net was a totally seperate EPROM, but now I’m wondering…..
      Doug, N0NAS.

  68. Hi Mike!

    I just bought a K 3 (non plus) and am waiting for shipping.

    Are you still available to burn new chips for this model? What’s the current source for them?

    Thank you so very much. Trying to keep the dream alive!


  69. hola buenas tardes soy walter radioaficionado Argentino LU1ABV ,TENGO UN kPC-3 no plus y nesesito armar un cable desde el tnc a la pc,pero mi puerto serie es de 9 pines coo debera hacer,ya que el cable que usaba antes es db25 de abos lados,pero este pc solo tiene db-9.

  70. Are you missing your clock?? does your tnc have the dallas DS1215 phantom clock installed…. many users did not have the system clock in the tnc.. its a nice feature to add.. not hard to do either.. in my issue i used the DS1315 and was found easily for less than 5$ online from asia.. the chip requires a 32,368khz clock crystal padded to 6pf on each side for a total of 12pf as these are typical dozen for 2$ ect.. in the KPC3 Non Plus… located between the eprom socket and the battery is jumper J5 and must be cut for the addition of the clock to be installed… the crystal is soldered to the board at position x3 next to the battery holder… however.. i simply inserted the crystal into pins 1 and 2 of the DS1315 for testing.. works like a charm.. with out soldering.. * the indent for pin 1 is positioned to the right as you face the front of the tnc.

    • Thank you so much for this information. I can’t however find the 6PF capacitors to add to the crystal i have on hand.
      what type are they?

      • Most of the KPC-3/3+ come without the clock chip or 32KHz crystal, they just have the chip socket. Either the original Dallas DS1215 clock chip or the newer replacement DS1315 clock chip will work in the TNC. Be sure you order the 5 volt DS1315 chip for the KPC-3 TNC.

        When you buy the 32KHz crystal, they have a specific load capacitance rating if you want an accurate clock. If you look at the DS1315 clock chip spec sheet, it will have a spec for how much load capacitance it provides within itself. To make the chip and crystal work together, you need to add enough capacitance to make the up difference.

        When I check the DS1315 spec sheet, it says the chip provides 6pf of load capacitance. The 32KHz crystals I used want a 18pf load capacitance. That means the crystal wants 12pf more than the chip provides. I think I used an 8pf or 10pf SMT capacitor across the crystal, assuming the PCB provides 2pf to 4pf by itself. The result was close enough that the clock chip was fairly accurate.

        On the PCB, the space between pins of the 32KHz crystal are just about right to solder an 0603 SMT capacitor between the pins. In reality, any size from 0603 to 1005 should fit.

        73, Doug Reed, N0NAS.
        Email my callsign at the usual suspects.

  71. How can I check that my memory upgrade is working?

    KPC-3 (non plus) here with V8.2 FW. I upgraded the SRAM to 512Kx8 using Digikey pn AS6C4008-55PCN chip. My board already had a 3 pin header on J6 and I moved the jumper from the two pins closest to the front LEDs, to the 2 pins closest to the SRAM itself.

    The max PBBS setting I can do is 118. Does this sound right for a 512Kx8 SRAM on the KPC-3?

    • Replying to my own post. Ends up even though my board has a 3 pin header on J6, there was still a trace short between pins 1 and 2 on the underside. I cut that trace, left the jumper on the two pins closest to the SRAM and now my max PBBS size is 480. Much better!

3 Trackbacks / Pingbacks

  1. W5BBS – Broken Arrow Amateur Radio Club » Blog Archive » Kantronics KPC-3 TNC Availability
  2. Got an old KPC-3 TNC? Want to use it for APRS? » Dave Santoro, W2DHS
  3. Fear and Loathing in EPROMs | Project Bytes

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