SSB Installation Tips

Tech Net Library

SSB Installation Tips

A Professional Shares Advice

by Bill Trayfors; Cruiser and professional SSB installer

SSB Installation Tips


There's much you can do to remedy poor performance problems from your Icom 802. Here's my list of solutions that work best.

1. DO NOT connect the main radio unit to ground, despite what Icom says. This creates ground loops.

2. Older 802's had several design problems; unfortunately, these are very prevalent in the cruising community. One is the so-called "clipping" problem. This was caused by a stupid design for an SWR monitoring/response circuit, departing from the very good practice of virtually all SSBs for over 30 years. Basically, the 802 is VERY susceptible to any elevated SWR level, and clips (cuts off) speech, making the transmissions unintelligible. Icom finally admitted the problem, and it's been fixed in the new rigs. Older rigs can be returned to Icom for a free fix.

3. Older 802's also had a "low talk-power" problem, as identified and described by Gordon West, among others. This was because the rig, as designed, could not pass FCC Type Acceptance with the speech compression turned on. So the radios shipped with it turned off, and only cooperative dealers -- NOT Icom America -- could turn it on. Gordon West recommended that all radios have speech compression turned on. RECENT UPDATE: Gary Jensen at Dockside Radio has tested some of the new ones, using a 'scope. He finds that there is NO DIFFERENCE with speech compression turned on or off, leading to the belief that Icom/Japan has bypassed the function in hardware.

4. Power to the radio. All SSB's should take their power DIRECTLY FROM THE HOUSE BATTERIES, using AWG 6 cable for runs up to 20' or AWG4 for longer runs, with appropriate fusing located on BOTH the positive and negative cables and very near the batteries. Only three types of fuses are acceptable under ABYC recommendations: ANL, Class-T, and MRBF (the new terminal fuses). I like the ANL and the MRBF's. Note that normal breakers are NOT acceptable (they don't have a high enough Ampere Interrupt Capacity), but the new Blue Sea Systems breakers with very high AIS are OK. The reason for taking power directly from the batteries, and NOT from the panel, is to avoid RFI both ways, i.e., from the radio into other onboard instruments and from other onboard devices into the radio.

5. The RF ground system, however configured, should be connected to the tuner ground lug ONLY. The KISS-SSB radial ground system, by itself, usually works very well. There are LOTS of ways to effect a good RF ground. Ground plates are unnecessary. Radials work well. So, too, do aluminum toerails, pushpit/lifelines/pulpit complex, s/s rudder posts, big swim platforms and arches, s/s rub rails (like on IPs), etc., etc. No need to connect to the keel, the engine, all the tanks, etc. No need for "100 sq. ft. of copper". These are oft-repeated and dead wrong urban myths! And, round wire works every bit as well as copper foil. Hey.... aren't dipoles constructed of wire? And aren't they effective?

6. Coax. While RG-8X between the radio and the tuner works OK, I much prefer RG-213 or, better, RG-214 which is double-shielded and helps to avoid RFI.





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