Coax and Connectors
The importance of a well constructed feedline system cannot be overstated. After all,
the purpose of the amplifier is to provide approximately 2 S units (12+ dB) of
improvement in your radiated signal. All too often, installations are encountered where
cheap/poor/under-rated/old coax and connectors are probably responsible for at least
one S unit of degradation. This means you could have bought a 375 Watt amplifier and
achieved the same radiated signal by buying good quality feedline components! Use the
lowest loss 50 ohm coaxial cable you can get your hands on. Use new, clean
connectors installed per the manufacturer’s recommendations. Clean the connectors
after soldering them, and before mating them with the amplifier. Make sure any excess
solder is removed from the connector, likewise any fragments of braid etc. Never use
old coax, which may have had moisture penetrate under the jacket. Run the coax in
straight lines as much as possible. Support it frequently using non-compressive clips so
that it does not hang or stretch under its own weight. Avoid sharp bends (most
manufacturers will specify a minimum bend radius for their product). Make sure the
transition from feedline to antenna is waterproof. Provide for disconnection of the
feedline when not in use.
Air Flow
It is critical that the 99 air flow is unrestricted in any way. Keep the top of the amplifier
clear of any restrictions. If you are mounting the amplifier in a console, make sure that
the exhaust air is properly and fully removed from the console. Poorly designed
consoles can result in outlet air being drawn back into the amplifier air intake and
recirculated, getting hotter and hotter, resulting in degraded amplifier performance or
even failure. If you are designing your own console, consider putting in additional fans
and/or ducting to deal with waste heat. Try to minimize the possibility of dust or other
contamination getting drawn into or falling on the amplifier. It is also advisable to
periodically clean the dust out of your amplifier for continued flawless operation.
RF Safety
The FCC requires users to check their installations for compliance with published
values for allowable exposure to RF fields. This information is available in ARRL
publications, FCC printed rules, and on the web. Radio Alpha Products strongly
recommends that this be done for any installation, both fixed and at an expedition or
contest site.
If you have any questions regarding engineering your 99 into your amateur radio
station, do not hesitate to call Radio Alpha Products Alpha Technical Support.
Radio Alpha Products Inc. ® Alpha 99
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