What radios work well for 9600 baud?

n7ipb's picture

Most hams get their introduction to packet radio via 1200 baud and tnc' s connected to standard voice radios. Unfortunately when you go to higher speeds voice radios just won't cut it.

Higher speeds require that the radio have a wider bandwidth, clean unemphasized output and rx and tx turnaround times that are well under 100ms. Despite what manufacturers claim, none of the '9600 ready' amateur radios work well at all.

That's not to say that there aren't radios out there that work, just that it's unlikely you will be satisfied with any of the typical radios provided by ham manufacturers.

So, what do you use?

First, there are numerous older commercial radio's that can be converted to the ham bands, and that will work well. Radio's like the GE MVP, GE MASTR II, Motorola MITREK, Motorola MICOR, Motorola MAXTRAC and others. A little bit of web searching and you can find all kinds of conversion info.

Second there are radios designed for data that we've determined will work well.

- The TEKK KS series http://www.paccomm.com/tekk.html data radio was among the first to be used. We have a lot of them inuse and they work well. It's a crystal controlled 2 watt UHF radio that originally sold for around $150. They are no longer being sold by the manufacturer but can be found on Ebay occasionaly.

- The TEKK http://www.tekkinc.com/products/data/sd-5200.html synthesized radio will also work, although we don't have a lot of experience with it.

- The MAXON SD-125 synthesized radio when modified with wider IF filters also works well. You can either do the mods yourself, or buy it already modified from PACCOM, or unmodified from outfits like RFWIZ http://www.rfwiz.com/Maxon/DataRadios/SD-125V_SD-125U_DataRadio.htm. Their latest price was $181.

- The WIMO http:www/wimo.com/frameset_e.htm PRD-70 synthesized radio is our current best choice. It's a 16 channel radio, with power selectable as 1 or 10 watts. It sells for 195 EUR (about $240 US), has fast turn around times and works great. RECOMMENDED

- Then for those that have a big budget there is the SYMEK http://www.symek.com/g/index-g.html TRX4S High Speed Data Tranceiver http://www.symek.com/g/trx.htm. This is an excellent example of a radio designed for data from the ground up. It has various filters to allow it to operate from 9600 to 153,600 baud. It's tx/rx turnaround times are under 200 usec. The downside is the price, currently it's going for 936 EUR for the UHF model which is about $1150 US. This might be just the thing if you're building a repeater and have a big budget, but is just a little out of line for the average station. The KeyTower site uses a pair of these for the repeater so we know they work well.