hill said:
Why hf - but not uhf - vhf ... I mean, if I'm doing 100 watts pep at 440mhz ... or what about even 25 watts @ 900mhz - 1,200mhz ... that seems like it'd be just as potentially adverse on unshielded equipment. Similarly, if my beam is pushing 1,500 watts from 50' - 100' away from the leaf - but directionally facing the Leaf ... I duno ... it just seams like Nissan would have / should have provided for such contingencies. I don't suppose there ever going to be any specifics on those thresholds.
I am pretty sure -- but not certain -- that Nissan has subjected the Leaf and guts to a lot of different Electromagnetic Compatibility testing. However I would guess that since Nissan didn't figure the Leaf to be a common carrier or law enforcement vehicle, they didn't do the EMC testing for RF in the near field to various Leaf innards. They may have this compatibility by default due to some other EMC design criteria.
Your example of 100 watts pep on frequencies from around 450Mhz and up don't reflect the actual level of RF radiation inside a particular spherical area around the emitter (antenna, mostly). Remember that PEP is "Plate Envelope Power" and does not mean the same as "key down" or continuous wave transmission. There are no modern transceivers which are advertised as "200 Watts on SSB" which would withstand continuous output transmitting.
I'm sure you know that the old time transmitters and transceivers which were designed for AM and CW and then, oh by the way, SSB, have power supplies and final amplifiers which will go key down for just about ever. But, compare the Collins KWM-1 which could run AM transmission for ever with a modern day solid state rig which may not even HAVE AM capability. Different strokes for different folks: The KWM-1 and similar rigs were designed for hams who did round-table AM rag chews -- key down maximum output for the full 10 minutes allowed by the FCC rules between station ID.
There are still some of those on 40 and 80 and 160 meters and to hear their signals is to hear a lovely complex and wide-band audio signal. I know one fellow who has a home brew amplifier for his AM rig and runs a full one thousand watts key down -- he has 813 tubes in the final amplifier (not 811's or 812's) -- and a power supply which must weigh 150 lbs.
When you look at a modern solid state transceiver, particularly as installed in a car or truck or boat or aircraft, grounding and bonding are essential. Otherwise, you will get RF burns from metal parts of the vehicle and electronics inside the vehicle will be toast, for the most part.
I always like the story of the Psychological Operations folks who flew ,missions over Vietnam. Their first attempt to operate a 1000 watt standard broadcasting station FM transmitter resulted in the aircraft "going dark" the moment the transmitting switch was flipped. Going Dark is also known as "oops!" unless you are in flight then it is time to earn your flight pay. Fortunately the a/c was on the ground but almost every piece of electronic gear, from the radar to the altimeter to the IFF to the pilot's relief tube had to be replaced.
With respect to the vehicle situation, especially the Leaf, I would be very careful about operating a transmitter in a frequency range of below 30Mhz and at a higher than 25 watt continuous carrier near the Leaf.
I am not sure of the RF field radiation at, say, 50 feet from a 6.5dB gain yagi running 1KW on HF and pointed over the Leaf. That might be an interesting calculation exercise, all things and variables considered. I know for sure that my 10 watts on 7.035 Mhz using a vertical whip antenna or a remoted NVIS antenna some feet away has not effected the Leaf; neither had the VHF/UHF radio operation at around 50 watts continuous (FM). But, remember, YMMV!
73 es GL
Dave
N4CVX
