MFJ-1270 & MFJ-1274 Digi Setup

Here are the settings that we used installing the WA6YLB-3 digipeater in the San Joaquin Valley, of central California. Please note that  the settings are for Paccomm version 4.0.0 or greater EPROMs. Its my understanding the latest version out is 5.0.0. Version 5.0.0 allows for options for digipeating only once etc. You can also embed your remote access password in JUNK characters so it wont be known. See PACCOMM.TXT at

If your installing this Paccomm TNC200 firmware in a MFJ1270C, you need to perform the following modification.

Paccomm's tnc200 firmware will work "AS IS" in an MFJ1270B,1274B tnc without any modifications. If you happen to install it in a late model 1270C, you must do a couple of things to return a 1270C model to basically a 1270B configuration. It doesnt work in a 1278 at all.

The 1270C version tnc, as shipped by MFJ, has two 32K static ram chips plus the firmware (32K also) installed on the main board. The Paccomm tnc200 firmware was written for only a single 32K static ram chip. The modification below is covered in the 1270C manual as for use with NET ROM node software, and is paraphrased here. It is very simple, and doesnt hurt the tnc in any way, and the tnc can someday be returned to MFJ firmware by reversing the steps.


After removing the lid, look for U40 , a .3 wide 20 pin IC next to the large IC's.

Remove U40 and tape it upside down on the state EPROM U6 so that if some day you want to return the tnc to MFJ firmware you will still have U40 around. U40 is used to bank switch between two 32K ram chips.

Remove IC in U24. Hang on to it. You will want re install it if returning to MFJ firmware.

Put the Paccomm eprom (27C256) firmware in U23.

Add a shorting jumper on JU16 near pin 5 of U23. This selects only one ram chip, instead of the bank switched ram that they use with MFJ firmware. JU16 is shown on the schematic.


Features: 4 aliases, Call-swapping (Mycall in place of Myalias callsign upon digipeating) and digipeat once. Also two paths for beaconing the position of the digi are availible. Remote control of the digi and personal message system are possible. (and recommended)

Here are the settings we used. Some of the settings pertain to use of the TNC at a users station. Only the settings that are unique to Digipeater use are mentioned here. It is possible to remotely set up the TNC with minimum settings, and connect to it and "fine tune" the settings remotely. Make sure the remote sysop stuff is turned on before doing so.

(PASSWD needs to be installed too!)

MYCall WA6YLB-3 <- digipeater callsign

MYPcall WA6YLB-7 <- Personal Message System callsign

RMTcall NO6X-9 <- remote operation callsign

MYAlias STONY <- this is the site name - could be state name.

MY1alias WIDE MY2alias RELAY

MY3alias TRACE <-- actually TRACE isnt used much any more. TRACEn-n is.

DIGipeat ON <- kinda helpful to have on

Beacon EVERY 120 <- this beacons the first path every 20 mins.

LOCation EVERY 120 <- this beacons the second path every 20 mins.

BText !3642.40NT11901.44W#PHG5830/A=004320/W-R Stony Flat

LTEXT !3642.40NT11901.44W#PHG5830/A=004320/W-R Stony Flat

| | |

Puts T in digi star| wide relay for old APRS vers.

(for TRACE) Altitude of Digi

Unproto APRS VIA KF6HJO,W6BXN,WB6MFV-3,W6CX-3,WR6ABD <-1st path

LPATH APRS VIA W6UR-1,KD6KQ-3,IYK <-2nd path

CONOk ON <- allow user to connect to digi to get Ctext

CMSg ON <- now give them the Ctext msg

CText Not a NODE. For more info about this DIGI, please connect to

WA6YLB-7 <- this is the message they get when connected

CMSGDisc ON <- then the digi disconnects them

HId OFF <- make sure this is off!

(this is what they get when they connect to MYPcall)

STExt No Forwarding. Stand alone Mail box. For info, read MSG 1

REtry 15 <- retry on a connectUIMODe OFF

USers 3 <- allow up to three users on BBSCONStamp OFF

LOGonmsg OFF PMs ON <- allows users to get message on PMS

REMote ON <- allows remote control use

REMSysop ON <- must be on to remote access it.

PASSWD place up to 31 characters here to respond to the

character vs position question. Make yourself a look

up table I.e. "Mary had a little TNC" would be:

Mary had a little TNC 000000000111111111122


And when the digi asks for 20,01,08,11,17, you type in

NMd e as your response. Upper/lower case matters

along with spaces!

We entered a message via the MYPms callsign, and left a message about the

repeater. This is helpful for visitors.

Stat : PR <-this MSG is what the user sees

Posted : 00/00/00 00:00To : ALL From : WA6YLB @ BBS : xID :

Subject: Information about this digipeater

Hello Fellow users. This digipeater is located in southern Fresno County

south of highway 180. This digi runs the latest Paccomm TNC200 software

version 5.0.0 and supports call swapping (places MYCALL inplace of any

alias callsigns [WIDE,RELAY,STONY,TRACE]) upon digipeating a Unprotocol

UI packet. To contact sysop, please email to: [email protected]

-or- via packet: [email protected]#CCA.CA.USA.NOAM Please enjoy the efforts

of Kurt KF6HJO, Mike NO6X and Byron WA6YLB.

Make sure you set the CLOCK in the tnc. This can be done remotely

with the DA command. When you do, the J command within the PMS will

have timestamp on them:

CMD(B/H/J/K/KM/L/M/R/S/SR/V/?)> <-helpful to know what the digi can

J hear.

WA6YLB-1 USER 06/23/97 13:59

N6QOG USER 06/23/97 13:59 <- calls w/o * are heard direct.

KF6HJO USER 06/23/97 13:55

KC6YRU * USER 06/23/97 13:54 <- a * shows it was heard via another

WA6YLB USER 06/23/97 13:54 digi.

W6BXN * USER 06/23/97 13:54

KE6FOA * USER 06/23/97 13:54

W6UR -1 NODE 06/23/97 13:52 <- X1J-4 node

AC6KT * USER 06/23/97 13:49

WA6YLB-3 * USER 06/23/97 13:47

KD6DX * USER 00/00/00 00:00 <- when clock isn't set, time is 0's.

KF6HJO-12* USER 00/00/00 00:00

WA6AFT-3 * USER 00/00/00 00:00

W6IKR * USER 00/00/00 00:00

BFLD USER 00/00/00 00:00

WA6FQM * USER 00/00/00 00:00

WH6DT * USER 00/00/00 00:00

KF6HDO * USER 00/00/00 00:00

KE6AFE * USER 00/00/00 00:00

N6TBQ * USER 00/00/00 00:00

WR6ABD * USER 00/00/00 00:00