Field Day Urban Legends
The Engineering Web
Myths and Legends that have, somehow, cropped up in vain attempts to break FCC rules just because it is Field Day.
Field Day Urban Legends
Dispelling Myths about Field Day
Laughable assumptions are made every year at Field Day about which Part 97 and/or ARRL contest rules can be laid aside for the weekend.
- There is no 15 minute on band rule for Field Day.
- When asked about this very question, the ARRL responded to me with several comments including:
- "the rule requiring a station to stay on a band for 15 minutes once it had made a contact was removed"
- and "Don't fall into the trap of trying to impose generally accepted contest rules on Field Day. Field Day is an operating event that traditional contesting rules don't necessarily apply too well to."
- and "Bear in mind that 90% of the Field Day participants have no clue what a 10-minute or 6-band change rule is about. To them, they try 10-meter phone, make a couple of local Qs then discover that 10-meters isn't open. Is there really a valid reason for making them stare at the transmitter for 15-minutes before moving on?"
- Essentially the message is relax, it's Field Day not Sweepstakes.
- The FCC allows exceptions to the rules for Field Day.
- OF COURSE NOT
- Not at all. Our Part 97 rules apply 24/7 all year long.
- Field Day operators inherit the frequency privileges of the call sign trustee and/or licensee.
- FCC rules are not exempted for Field Day.
- From Section 97.3 - "(13) Control operator. An amateur operator designated by the licensee of a station to be responsible for the transmissions from that station to assure compliance with the FCC Rules."
- Field Day Operators are Control Operators of the station they are sitting in front of.
- "(b) A station may only be operated in the manner and to the extent permitted by the privileges authorized for the class of operator license held by the control operator."
- Each control operator can only operate on frequencies they are personally licensed for.
- You don't inherit Extra privileges if you are a General working at any station unless the at-your-side control operator of your station happens to be an Extra and is watching over you.
- I am a Technician and operating the radio while the person running the log is an Extra so I can use Extra Frequencies
- Sure why not...
- Just call the logger the control operator, but you are spinning the dials. He/she is there to keep you from doing something silly.
- If this Extra Class logger gets up for some coffee, you are supposed to not transmit until he/she gets back.
- The ARRL Field Day rules don't talk about "Control Operators"
- In an apparent attempt to mitigate gross volations at GOTA stations the ARRL has "Rule 126.96.36.199. As per FCC rules, this station must have a valid control operator present if operating beyond the license privileges of the participant using the station."
- During Field Day the Control Operator must sign portable by appending /P to the call sign for code or say "Portable" after the call on Phone.
- The rules were changed some thirty years ago. You do not need to sign as portable for Field Day.
- I brought the radio and I am an Extra so all operators Extra or not have Extra privileges.
- Privileges travel with the control operator not the owner of the radio. See above...
Field Day tends to bring out the 'best of breed' in BS about the engineering involved in operating radio equipment safely and productively.
- Coaxial cables never radiate
- If the load at the end of the coaxial line (antenna for example) is not a perfect load, RF current will flow on the outside of the coaxial cable shield all the way back to the radio creating RF shock hazards.
- Field Day antennas are rarely perfect so always assume you need to deal with RF currents on the outside of the coax.
- Coaxial cables sometimes radiate
- Consider any coax attached to any antenna part of the radiating portion of the antenna unless you provide some means to "RF Choke" the transmission line near the antenna feedpoint
- Parallel transmission line always radiates
- So long as the currents in each wire of a parallel transmission line are equal and opposite, the resulting combination of electro-magnetic energy in the far-field equals near zero. It is true the near field energies do not sum to zero and this is why parallel line must be kept away from conductive objects.
- Parallel transmission line sometimes radiates
- If the antenna is not balanced and/or the transmitter is not driving each line equally, parallel transmission line will radiate.
- There is no way to prevent interference between stations at Field Day
- Use a preselector or try various coax stub techniques covered well in QST
- I have a vertical set up with lots of radials. I don't need to worry about RF current on the outside of the coax feeding the vertical antenna.
- The outside of your coax is just another radial to the antenna and will absolutely bring current back to your station and cause potential RF shock hazards. Granted, if you have a lot of radials the current may be small, but certainly not zero.
- Use some kind of RF Choke or Feedline Isolator on any vertical antenna if you really want to be proactive in keeping RF out of your tent.
- My Field Day Vertical Antenna manual suggests using radials, but a ground rod is all I really need
- A good field of radials laying on the ground couples, very effectively, the critical shield current to Earth via AC coupling.
- A ground rod pounded into the Earth is a poor coupler of shield current to Earth.
- A ground rod is pointless for RF purposes if you have a good radial field (However, it is still a good idea for static and lightning surge dissipation.
- A ground rod is spectacularly better than nothing at all. If this is the best you can do to "Earth" your vertical antenna that wants radials, by all means do it.
- Long-wires for 14 MHz and above suck
- Too many folks are getting results with them.
- Field Day is an excellent time to make the most of a little. Try a long wire against a counterpoise and point the wire towards the middle of the country.
Dangerous Technical Issues
Once again Field Day tends to bring out the 'best of breed' in BS about the engineering involved in powering our radio equipment from generators, etc.
- I have a generator meant for house backup power and it will be just fine for Field Day as is.
- Generators meant for backup power and, thus, attached directly to the home's AC power panel, do NOT connect their Neutral and Ground together. They rely on the panel for this critical connection to remain in the panel and not with the generating equipment.
- YOU MUST CONNECT THE NEUTRAL AND GROUND TOGETHER IN YOUR CORD for use as a stand-alone field generator.
- Alternatively, your generator may provide an option to "bond" the Neutral to the Generator chassis and Ground wire on the outlets.
- I have a generator meant for a work site (construction for example) and it will be just find for Field Day as is
- QUITE LIKELY, but verify
- Construction work-site generators tend to bond the Neutral to the chassis and the ground wire in the receptable and are meant for precisely the type of operation Field Day presents
- Connecting the generator's chassis to a nearby ground rod with copper wire is a good idea
- Connecting the ground wire of the power arriving from the extension cord to the station ground is required.
- Check your power supply to see if it is already doing this ground connection to your station ground for you. That is probably enough
- Remember the role of the ground wire in the extension cord is to provide a pathway for leaking AC power back to the generator so the circuit protection device in the generator trips and protects you, your cord and your equipment.
- It is certainly not an RF ground
- I went ahead and used plugs for my custom cables as I could not find any receptacles for power cords my size
- If you have plugs on both ends of a power cord you clearly do not have the skills necessary to continue working with any AC power issues. Leave this to the electrician in your ARC or get out of Amateur Radio altogether before you kill yourself or someone else