Tigertronics BayPac BP-2M Multimode Modem

Reviewed by Rick Lindquist, N1RL - Senior Assistant Technical Editor ARRL ( QST - April 1997 )

QST Cover

Whatís that old saying about good things coming in small packages? Well, that certainly applies to the BayPac BP-2M multimode modem from Tigertronics. This is a teeny, tiny little TNC thatís only slightly larger than the typical DB-25 connector on the end of your printer cable. Itís software driven - the actual TNC emulation happens in the software and the PC thatís attached - so how well it works highly depends on the quality of the program you run.

Packet radio was the reason I fell in love with the little BP-2M. Friends have been after me for months to get on the local packet node, but for a variety of reasons, I never got around to it. Yes, Iíve got a "conventional" (and much larger) TNC I bought several years ago. But it was hooked up to my HF rig for RTTY. Putting it on packet meant having to wire up another connector, then resetting the modem. Besides, my only 2-meter radio at the time was in my car. Oh, the bother! So, I kept putting it off.

Finally, I got a 2-meter radio inside the shack, and I decided to give the BP-2M a try. An optional interfacing cable let me hook the little box up to the DB-9 serial port on an aged 80286 laptop computer. I didnít avoid having to wire up the BP-2M cable to the microphone input, PTT line and audio output circuits of my 2-meter transceiver, but it was not nearly as painful as Iíd envisioned. The cable interfaces with the little TNC via a telephone-type modular plug. Tigertronics supplies very thorough Installation and Operation instructions with the unit. By the way, to use the BP-2M with an HT that does not have a separate PTT line, you need to install a little jumper (supplied) on the unit that activates an internal 3k ohm keying resistor.

Since the quality of the BP-2Mís operation depends almost entirely on the quality and compatibility of the software youíre running it with, Tigertronics supplied some software that it knew would work nicely with the BP-2M. I installed the two disks on my hard drive and fired up the BPMODE program. As John Olson, WA6IKO, of Tigertronics explained to me, the BPMODE program makes the BP-2M "reconfigure itself into an entirely different modem" depending on the settings you choose. Itís also a nice little diagnostic and calibration tool to make sure youíre transmitting tones at the correct levels (the BP-2M has a little level adjustment, but you shouldnít have to touch it), have your volume control set high enough, and that the unit keys the PTT line in transmit. You must run BPMODE to set the BP-2M for the modes(s) you intend to operate. Itís a very simple program, and since it runs under DOS, you can put that relatively primitive PC youíve had sitting around to good use in the ham shack.

One note for Windows wonks: Tigertronics says you canít run the BayCom packet software under Windows, not even as a full-screen DOS application. This has to do with the way Windows handles system interrupts. However, a relatively new packet program, WINTNC ver 1.01, available as shareware (the latest version is Rev F), will run under Windows 3.x and Windows 95, although Tigertronics warns that itís "not quite up to par with BayCom in performance". You still canít run your multimode software in Windows, however. Tigertronics says this will always be the case. For some at least, this might be a major disadvantage to the BP-2M. The latest (and last) shareware version of BayCom is 1.4. This is now a commercial product, so getting the latest version now will cost $20 (plus $5 S&H). As the instructions declare: "BayCom requires the total undivided attention of the computer to work reliably". You should not be running any TSR (terminate and stay resident) programs either.

Once Iíd determined that the unit was hooked up correctly, I set the unit to Mode 1, which is VHF/UHF packet. Then, I ran the BayCom program included with the unit. The program was written by DL8MBT, so donít be surprised when you see occasional DOS command-line messages in German. Once I got familiar with the common packet commands, I was able to log onto my local packet node the first time out (Iíve become a pretty regular visitor, and being on the PacketCluster was a real help during the Heard Island VK0IR DXpedition). BayCom offers a split-screen mode: what you send is on the top half of the screen; what you receive is on the lower half of the screen.

After returning to BPMODE to reset the BP-2M to work with the multimode software (Mode 3), I tried a copy of the HamCom shareware program - also from Germany - to run RTTY. Once I got it set up correctly and learned how to navigate the program, it worked super. The BP-2M is so small (and requires no external power source) it puts mobile RTTY (or other digital modes) within easy reach! (If you look carefully at the front cover of March 1997 QST, you might notice that Iím using a BP-2M hooked to a palmtop PC to run 2-meter packet with a venerable ICOM IC-2AT.)

We also successfully tested the BP-2M on FAX, SSTV, CW and AMTOR.

Tigertronics Web site, http://www.tigertronics.com, offers more information on this unit, plus the latest software updates and links to sources of shareware that Tigertronics has found to be compatible with the BP-2M.


Bottom Line:

A neat and inexpensive little package that puts packet and other digital modes within easy reach of anyone with a PC - even an old DOS clunker.

Manufacturer: Tigertronics Inc, Box 5210, Grants Pass, OR 97527; tel 800-822-9722; 541-474-6700; fax 541-474-6703. Manufactures suggested retail price: BP-2M multimode modem, $69.95; model BP-2 packet-only modem, $49.95; nine-pin to 25-pin serial adapter, $6.