Things New Hams Should Know if Operating on Amateur Repeaters and Using Crossband Repeaters

Operating on Ham Repeaters – Things You May Not Know

Written by Bob Gass N4FV

You just got your license and first radio.  Chances are it’s a handie-talkie and you are ready to try it out.  Before you start keying repeaters and testing you should know a few things about operating.

§ 97.119 Station identification.

(a) Each amateur station, except a space station or telecommand station, must transmit its assigned call sign on its transmitting channel at the end of each communication, and at least every 10 minutes during a communication, for the purpose of clearly making the source of the transmissions from the station known to those receiving the transmissions. No station may transmit unidentified communications or signals, or transmit as the station call sign, any call sign not authorized to the station.

Station in the above rule section means any transmitter you own and able to transmit on or have control of (transmitting on someone else’s radio).

Unidentified transmissions –  On HF someone tunes up an antenna with a carrier.  Or throws a comment into the conversation, usually to stir the pot in the conversation.  No callsign is given.  It also happens on repeaters to see if the repeater is working or if a radio can be heard. When it happens on a repeater, its called “kerchunking” the repeater.   You briefly activate the PTT on your radio and the repeater comes up.  If the repeater has not been keyed up in the past 10 minutes, it will usually identify in Morse code or voice.  Then you move to another repeater and do the same thing  (“kerchunk” it).   Although it might be permissible to “kerchunk” the repeater to see if you are able to get into it, it is not permissible to “kerchunk” it and then remain silent or move on to another repeater WITHOUT IDENTIFYING YOUR TRANSMISSIONS!  Good etiquette is to identify your transmission or series of transmissions.   Stating your callsign and you are testing or listening is acceptable.   Not identifying is a violation of the FCC rule above.

Some repeaters have a feature called “anti-kerchunk” that either delays the transmitter from keying when first detecting a signal or allows the carrier to immediately drop if the signal is not sustained for a certain period of time.  The first method cuts off a second or two of voice because of the delay in the transmitter turning on and the second method does not allow the transmitter to stay turned on during the time window so it immediately turns back off and you get no indicator the repeater is active.

There is nothing more annoying than the serial “kerchunker” that has to check every repeater frequency in their radio, especially those that do it on a daily basis.   Over the years I’ve heard  a few that had a daily routine.  These “LID” operators know they are in violation but like criminals, just don’t care that they are violating the rules.  Just because you can “kerchunk” the repeater with your pitiful Baofeng with a 1 inch stubby duck doesn’t mean you will have a readable signal, it just means your radio can make enough signal to key the repeater and may be so noisey into it that your audio is not readable.

Can “kerchunkers” be identified?  Yes they can but it requires some time and monitoring on the part of the repeater owner/trustee.  Law enforcement uses fingerprints to place criminals at the scene of a crime.  “Kerchunkers” always leave a “fingerprint” that can be traced.    Each transmitter has a unique keying  and CTCSS tone  signature.   When a serial offender’s signatures are captured , its just an issue of monitoring other frequencies/repeaters and identifying who the culprit is from captured fingerprints and identified transmissions.   Direction finding can also be used if the signal interval lasts long enough.

I listen to the local repeaters and no one is talking.

Are you someone that complains because you never hear anyone on a repeater(s)?  If you hear someone, do you answer them?   Get proactive!  Announce you are listening or monitoring.  You might be surprised that someone is actually listening and willing to talk to you.  Give someone time to respond.  Waiting 15 – 30 seconds after a call might not be waiting long enough to give someone a chance to answer.   Give it a couple minutes.  What time of the day are you making your calls?  Most people work day jobs so 7-3 might be a time when fewer hams are around.  Drive times (before 7 am and after 3 pm) are usually the best times to find someone on the repeater.  If you hear net activity, join in!  When the net ends, there may be some stations that hang around to chat awhile.

Where do you find repeater frequencies and tones?

Publications such as the ARRL repeater directory are only updated once a year.  A couple of good online repeater listings can be found at   Artscipub.com and  Repeaterbook.com.   Keep in mind that the listings are not 100% accurate and rely on user submissions to be kept updated.  Some repeaters may no longer be on the air or off the air due to technical or other issues.

Would you like to have your own repeater because you don’t hear anyone talking much on nearby repeaters or it would be “cool” to have your own?

Installing and maintaining a repeater requires technical expertise and good test equipment.  Otherwise you will pay someone lots of $$$ to help take care of it unless you have a good friend.  Site location is very important also.  If the repeater location is not high above the average terrain, little would be gained over just normal simplex communications. Getting access to a good site might require more money than you are willing to spend.  It might be in your best interests to help support one of your local repeaters rather than attempt to put one on, especially if you have no communications experience.  Many times the “Build it and they will come” attitude doesn’t work well for long.

2 meter repeater frequency pairs are very hard to get because almost all have been assigned to someone.  Even “buying” a 2 meter repeater frequency from someone and trying to relocate it does not guarantee the coordinator will allow you to move it to your location.   Putting an uncoordinated repeater on 2 meters may result in letter from the coordinating body demanding you remove it with threats of turning you into the FCC.  Before “buying” any 2 meter repeater frequency or investing in 2 meter repeater equipment, check with the repeater coordinator.

UHF repeater pairs are available and the cost to do a UHF repeater is much less expensive.  A 2 meter repeater duplexer will cost $500 plus on the used market while many good duplexers for UHF are priced under $250 on the popular auction site.   There is more surplus equipment available for UHF also.

Can my family or friends use a handheld or mobile radio to talk to me?

You cannot let your spouse, children, or anyone operate an HT, mobile, or base on any amateur frequency unless the person using the radio has an amateur license of their own with appropriate privileges or you are acting as a control operator (physically in their presence).  You cannot conduct any business via amateur radio except in very limited circumstances.   If you want to communicate with members of your family who do  not have amateur licenses, then you must use another radio service.  License free services such as Citizens Band (CB), Family Radio Service (FRS), Multi-Use Radio Service (MURS) are all legal for use by your family members.  Licensed services such as General Mobile Radio Service (GMRS) or Part 90 LMR might be more appropriate if you need to use radios for business use or longer range.

Simplex Frequencies

Communications that do not go through a repeater are called simplex.  The most popular ones are the national simplex calling frequencies on 52.525 mhz, 146.520 mhz, and 446.000 mhz.  There are specific frequencies assigned by SERA (Southeastern Repeater Association) for simplex operation.  Please do not pick a random frequency and operate simplex with another station.  You may be on or near a repeater input, weak signal reserved area, or satellite input and cause interference to other stations.  Bandplans are available at SERA or your recoginized repeater coordinating group for your area to help you choose appropriate frequencies for simplex operations.  Keep in mind that some simplex channels are shared with digital repeater inputs.  You should always check to make sure there is not a digital repeater operating on a shared simplex frequency that is within 75-100 miles of your location, as chances are you will cause interference.  There is a repeater in Greeneville TN that uses 147.420 as an input that is coordinated by SERA for repeater use and people in that area have been asked politely to move elsewhere, as it is a repeater input.

Cross Band Repeaters

A cross band repeater is simply a vhf and uhf radio that are tied together in a way that the  receiver of what one radio hears is rebroadcast over the transmitter of the other.  It is a sloppy, cheap way of extending the range of your handheld radio since many of the dual band mobile radios will work in cross band mode.  The reason I call it sloppy is you have to wait for the RX of the incoming repeater signal to drop before you can transmit back to it.  The reason I say it is cheap, is its very easy to do without any expensive things like duplexers.   The bottom line is you get what you pay for, something that works but not well.

One mistake a lot of hams make is choosing just any frequency pair for the handheld radio to use.  Refer to your repeater coordinating body approved frequency use list and choose a pair reserved for cross band use.  Failure to do this may result in interfering with someone’s repeaters input.

6 Meters – Repeaters or Weak Signal?

Weak signal modes are CW (Morse code), SSB (Single Sideband), and Data.   Operation on 6 meters for these modes are usually below 50.500 mhz.  The longest distance contacts are going to be made via weak signal and not on FM.  FM is not considered a weak signal mode due to it’s wider bandwidth and the amount of signal it takes to quiet the receiver.  FM operation is done mostly on the repeater inputs and simplex frequencies between 52 to 53 mhz.  You listen to the repeater outputs on 53-54 mhz.   Can you work long distances on 6 meter FM? Yes!  I recall an instance in 2002 where K4WS made his first 6 meter Alaska contact on 52.525 FM simplex from here in Tennessee.

Antennas for 6 meter FM repeaters for local operation (called ground wave) are always vertically polarized.  Using a dipole, random wire, or other type of horizontal antenna on a local repeater will usually result in your signals being weak or not being able to hear or get into repeaters that are within the ground wave (50-100 miles) range.   If there is a band opening on 6 then the horizontal antenna will work fine to hear and access a repeater or simplex station several hundred miles or more away for FM but not optimal for regional use for repeaters.   Bandwidth for antennas on 6 meter are not very wide so an antenna resonant for the weak signal area (50.250 center frequency) will exhibit high SWR on 52-53 mhz where most FM transmissions take place.  The opposite is also true with an antenna resonant on 52.500 mhz  exhibiting high SWR below 50.500.

Antenna Tuners

The appropriate place for an antenna tuner is at or as near as possible to the antenna feedpoint or used with 300/450 ohm wire feed line in your shack.    Connecting an antenna tuner inside your ham shack to coax does not lower the SWR of the antenna but fools your radio into thinking it is looking at an acceptable SWR.  There is still a mismatch and the power lost is dissipated as heat in your tuner and feed line.  Your antenna will not radiate properly.   A mismatched antenna results in the feed line  becoming part of the antenna system and radiates RF.  This can increase the possibility of radio frequency interference in your home and to neighbors causing interference to various electronic devices when you transmit as well as distort the radiation pattern of the antenna.