"Bjarke M. Christensen" bjarkeNG@grevestrand_punktum_danmark wrote in
:
Are you saying that the osc's in marine ht/ssb's are more stable that
the osc's in ham hf/ssb's ? Why should that be so ? If icom can make
it stable in the marine ssb; why don't they deploy the same technology
in the ham ssb's ? I guess freq stability is a must for hams as well
??
Yes, of course. Ham radio has only one channelized band, 60 meters a new
one, shared with government stations under a test for emergency comms in
places like Katrina. All the other ham bands are broad strokes of
frequencies you can operate anyplace in there you like. The radios have
10 or 100 Hz steps. Their master oscillators are cheaply made, not
temperature compensated much as there is no need. Most have a trimmer on
the outside of the radio so you can tweak it closer, yourself. Marine
radios have temperature-compensated crystal master oscillators accurate
to a standard. The M802 is:
Operating temp. range :
–30°C to +60°C; –22°F to +140°F
Guaranteed range : –20°C to +55°C; –4°F to +131°F
Frequency stability : ±10Hz (at –20°C to +55°C)
This exceeds the .005% of the FCC standard for type acceptance. Hell, 10
Hz is closer than the 20 Hz of an AM broadcast transmitter costing
thousands of times more. (Most AM transmitters, today, are within 1 Hz.
You rarely hear much of a beat note at night on frequencies you can hear
two or more stations transmitting on.)
M802 also exceeds other standards for unwanted emissions that cause
interference to other frequencies:
Output power : 150, 60, 20W PEP (Selectable)
Spurious emissions : –62dB
Unwanted sideband : 55dB
Carrier suppression : 40dB
Its design also keeps you on the right sideband, USB, and its computer
will not permit you to do technical things wrong users know nothing about
that any ham radio will easily do if you just bump a knob or press the
wrong button.
All this is designed so that operators with very limited or no knowledge
of radio transmitter operation can operate the marine HF radio without
causing undue interference to other services and users by technical
incompetence. It's why cop, business band, trunk radio and CB radios are
so simple...a minimal number of knobs to screw up. UNfortunately, M802
has way too many buttons and knobs for most of its owners to use. It
requires too much education the older SSB radios didn't need....Channel,
Volume, Squelch, PTT microphone are all they should have. Japanese pride
themselves in making anything they create into a technological wonder.
M802 should make them all very proud.
The other reason they don't make ham radios so stringent is
simple....money. You can see it in the difference in price between an
M802 type-accepted commercial radio and the Icom 706 ham rig. Few hams
will pay for a type-accepted commercial-grade radio. Hams are an awful
"cheap" lot. So, in response to the market...just like consumer
electronics everywhere...Kenmore, Yahoo and Icum make 'em as cheaply as
the market wants...just like that PoS TV in your living room.
When the 802 is enabled for ham (using the procedure you describe)
will it do both or do you have to toggle it back constantly ?
It will do both. But, make SURE you put it back to channelized transmit
before any Ship Inspections or you'll be busted. Pleasure boats are
pretty much immune from ship inspections, but, if you look at your ship
station licence from FCC, you'll notice they can come inspect your
installation at any time for compliance.
If I'm aboard, it's open so I can chat on 20 meters. If I'm not aboard,
being the only licensed ham, I switch it back so my captain doesn't try
to talk to BBC on 31 meters by mistake....one of his channels...(c;
You often hear that marine ssb's are difficult to use on ham, as they
are optimised for a fixed freq setting, and not for the more variable
freq used on ham. How big a problem i that ?
That is true of a lot of them. They are made to be channelized radios.
When Icom made the M802, some ham infiltrated the design team and had
them implement BOTH channelized operation, where the display shows you
what marine channel you are operating on...and...a beautiful frequency
display where the left knob chooses which digit to change with the right
knob, giving you coarse and fine frequency control, AND, made it so the
digit you're changing carries over when it switches anything from 9 to 0.
The right knob acts just like a ham VFO, in 100 Hz steps which is close
enough for hams. There's a little learning curve to switch the dials
between modes but once you learn how and use it it becomes second nature
very quickly. It's not a big problem at all on M802. The older and
cheaper radios don't have this feature making them useless...which is
what caused boaters to illegally use ham radios for marine radios in the
first place....that and PRICE.
Idont know you ham license structure, but where I live only the higest
license level are allowed to use more than 100w. Can the 802 be
configured to run only 100w on ham bands and 150w on marine bands ?
Yes. The M802 has 3 power levels simply adjusted by the front panel
buttons.
From the webpage:
http://www.icomamerica.com/products/...m802/specs.asp
Output power : 150, 60, 20W PEP (Selectable)
Another issue for your country is that I'm talking about USA type
acceptance and the FCC, Federal Communications Commission. Although our
government bureaucrats like to think they are omnipotent, they are not.
Your laws and radio regulations ARE different than our, but probably
accept FCC type acceptance as a matter of convenience. You may have more
lax laws than the USA. Check with your radio bureaucrats for guidance on
Marine installations. America has changed, recently. In the past, you
had to have a 2nd Class FCC commercial radio operator's license to
install and configure a marine radio. Owners were not allowed to do
anything to it but use it. Now, owners are allowed to install it as long
as the installation does not involve any adjustments to the factory-set,
type accepted internal settings. The computer and transistor broadband
amplifiers allowed this to happen as no radios require extensive tuning
like they used to back in the tube days. They're all plug n play.
I'm sure Danmark's radio bureaucrats have webpages about the laws,
regulations and requirements for your country.
Larry.