PSK31 with Buxcomm (markV) Rascal Interface and Quick Change Rig Cables.

Since the recent Digital Program at the IRC we have connected our Rascal Interface cables from our IC-756 Pro to our Dell Laptop computer and started receiving and transmitting PSK 31 using Winpsk that came on a CD with a lot of other data from www.BUXCOMM.COM.

Their $69.95 assembled cables with a “free” cable to your rig is on sale for…$39.95.

After reading the info with the Rascal and the PDF file with Winpsk we started connecting the basic plug and play cables. The main cables goes in the back of the IC-756 Pro to the Accessory Socket # 1 directly below the power cable connection. (Thus once audio and TX levels are set no adjustments are necessary on the front of your rig !) The other end connects to the “universal” socket on the Rascal Interface box & LED ( TX Light). Two cables with small audio plugs go to the computer. The white plug (RX) line out goes to the “Head Set” connection on the PC.

The green plug (TX) line in goes to the “Mike” input on the PC.

We only connected the RX line at first to be sure and not TX by accident during testing.

However, when both cables are plugged in it requires a re-adjustment of the receive level.

Also be sure and turn on your PC and bring up the Winpsk program before you turn on the transceiver, as the red light on the Rascal is ON and your rig will key up until the program is loaded and running.

To adjust the RX level, tune 14070.15 look for the water fall. Click on the yellow line at the bottom of waterfall to show most of the current transmission. Clicking at the top of the Yellow line starts at the current information being sent.

Under Settings on the “Top Menu” go to General: Enter your call, “check mark” Echo TX, use Slash zero, squelch = 75, AFC 100 +/- Freq range 200 start, 3500 end, and Com1 for PTT or to suit your PC system. Go back and bring up RX Level Adjust in the “Settings” menu and in the full left column (CD Audio) adjust as needed for proper receive level, not showing any “RED” only occasionally. A red signal and warning shows the level is too high. ( Ours was set on 3 ½ Bars from bottom)

TX Level Adjust: Under settings menu bring up TX level (left column “volume control”) start at bottom, equals lowest setting. Hint: Connect transceiver to a dummy load for testing. Set your RF output control to almost full output. (90%) Using F2 (BTU) or other short string adj TX level upward a little at a time from the above TX level in the “Settings menu”. Adjust to about 25 Watt out from your audio tones for a 100 Watt basic transceiver. Also remember to turn OFF any speech processing, and no ALC signal should show with your final settings. The idea is to have a “clean” linear signal to transmit the proper tones. (This part cannot be checked by you on your rig and should be checked on your first few contacts to verify you are not overdriving and causing splatter. (An IMD reading of -25 DB or so is generally acceptable from a received station.)

Be careful not to exceed the “continuous duty” rating of your transceiver. ( 25 –30 Watts is enough output on PSK) Note: Also set your TX frequency at about 1500-2000 cycles or higher.

A lower power output probably will be noted below 750 cycles in transmit.

On the Rascal interface, the ¼” hole is for a Philips screwdriver adj. For course TX adj.

Using a pencil I put a “dot” mark at 12:00 on the top side of the “ceramic X pot”, as a starting reference. Turn pot CCW to lower output, and work back and forth for the 25Watt output and the computer setting so neither is all the way at low end of the scale. My RX was 4 Bars up and

TX was 3 ½ bars up on the computer and about (9:00 on the pot or about ¼ open on the Rascal.)

(use a light touch on the trim pot adjustment, so it is not damaged!)

Now that you have a basic starting setting, it’s time to listen and see what is going on PSK.

Read the PFD file for Winpsk and look up any special feature you wish to study extra.

To receive a signal, click on the water fall (yellow) line at the top. Also using the L & R arrow keys will lock onto the next signal across the 200-3500 freq range. (AFC must be on.)

Likewise, double clicking on some ones call will put it in the Call Box. Also dbl click on their name and its into the “Name box”. Also highlight a word string and it will be in the word box.

Really neat and easy. As soon as you here a signal double click on the NET box and it will adjust your TX frequency to the callers frequency. Usually you leave NET in off mode.

To learn the “Macro’s” do a right click on them one at a time and see the help list build into the file.

You can use the standard one at first and as you become accustom to operating you can modify them and add new ones as you see fit.

On our first try at transmitting we worked a W5, W1, W6 and CT1 in Portugal, SM7 Norway on 20 Meters with 25 watts. All came thru with almost 100% letter perfect copy, which is not always the case depending on signal strength, conditions and a clean signal.

This was our first use of digital radio and it seems to be fun and provides yet another mode of operation in the continuing changes we see in radio and electronics today.

We also ordered a 2^nd set of cables for our IC-2720H VHF/UHF rig…which will just plug into the Rascal LED BOX and not have touch the computer connections for a quick change. An adjustment of the TX and RX levels will be needed to put in operation also.

Have fun on PSK most OP’s are friendly and helpful.

Bob Osterhous W9PSE.. Indianapolis, Indiana May – 2004