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Author Topic: Does anyone really know what impedance the 7300 will tune in Emergency mode?  (Read 1894 times)
K0UA
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Posts: 1348




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« on: September 15, 2017, 05:41:32 PM »

I have tuned some really far out there antenna loads in emergency mode on the 7300, and I believe the book say 5 to 1 SWR , but I know some of the antennas it said OK to are far from that good.. One one of the Ic7300 forums someon said it was 10 to 1.  Does anyone have equipment to really measure it.  I know it wont tune an end fed 160 meter inverted L on 80 meters.  But that would be VERY high probably around 5000 ohms?   What say you?
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K0UA
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Posts: 1348




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« Reply #1 on: September 25, 2017, 05:44:21 AM »

I guess no one really knows!   Grin
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ZENKI
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Posts: 1421




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« Reply #2 on: September 29, 2017, 09:45:05 PM »

Look at the ratings of the components in the amplifier circuit and from the VSWR you can easily calculate the failure point. Why would risk damaging the PA of the radio when tuners like the LDG are readily available for so cheap?

Besides if you are using the IC7300 in  an emergency scenario  you would be  much better off building a broadband antenna like the T2FD or buy one of the commercial  traveling wave variants like the Codan antennas.

Contrary to the folklore these are not antennas with a dummy load across them but viable antennas for emergency  and in country communications.  HF communications is not only about the Decibel DX Derby but about getting the message through.  Many government agencies, UN and the Red Cross  use these antennas across the global in their operations and they work  well in their intended role. Many airports also use them as their primary HF antenna.

These antennas are very easy to build.
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