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  • Civil Air Patrol Communications For Under Thirty Dollars


    This page is for INFORMATION USE ONLY.   The ONLY reason I have left it on this site is it proposes some interesting thoughts.   Read and learn, just don't do.


    Intra Squad Radio

    The legal CAP alternative to the information described below is the Intra Squad Radio. It is essentially an FRS radio on Federal-government-only frequencies. As such, it is legal for use by CAP.   I have not heard whether members were successful in modifying normal FRS radios into ISR compatible radios, but even if it is technically possible the legal status would be dubious.   Be legal, keep your Director of Comm happy, and buy an ISR.



    A great number of CAP members have supplemented their regular FM and HF communications with Family Radio Service (FRS) radios.   These radios are now available commercially for $20 or more, depending upon the "features" desired.   FRS radios can easily take place of the radios described on this page.   Their use by CAP, however, would likely be considered illegal by the FCC.   I'll quote another CAP member who said, "illegal comm is better than no comm at all."   He said it, not me.   FYI.



    This page describes how virtually any CAP member can very easily modify a crystal-controlled Citizen's Band (CB) radio for use on a CAP-only radio frequency.   That frequency is 26.620 MHz.

    I don't claim to be any smarter than any other person.   I'm a licensed amateur radio operator (no-code tech, you guessed it!), but that just means I can pass a couple of tests.   Really, that means I bought a CAP handheld radio and THEN decided to get a ham license to use its full capability!   I only know how to do this because (1) someone told me about it, (2) I asked a lot of questions, (3) I researched it, (4) I tried it, and (5) I'm willing to make and admit mistakes and accept help to perfect the conversion.

    Currently, a significant problem exists in Civil Air Patrol communications.   Most CAP radio traffic is on the 2 meter or lower bands and generally uses modified amateur radio service equipment.   That, in itself, is not a problem.   The real problem is COST.   The average member cannot afford to purchase a $200 HT or even more expensive HF gear when he or she will only use it occasionally.

    26.620 has been available for a very long time, but been desperately underused due to lack of public information.   I hope to help correct that with this page.   With only a little determination and $30 to $50, any member can own his or her own CAP radio.

    26.620 MHz is NOT the answer for everything and it is not a replacement for other communications gear.   It is merely a useful expansion of the current CAP radio system and one that is not utilized enough in current CAP ops.   The range of the hand held walkie talkie-type radios is severely limited.   At best, a member might be able to reliably communicate at the distance of about a mile.   Reports from the field indicate, however, that with a good base-station type antenna with good high placement can have a reliable range of 5-8 miles.


    If the range is so limited, then what good is 26.620?   26.620 is great for communications within a single ground team or for personnel working the flightline.   When a ground team leaves a vehicle on the road to go those final steps on foot, it is always a good idea to leave at least one member in the van to work the radios.   A mobile radio generally has much more power and frequency capability than whatever can be carried into the field.   If both the ground team communicator in the field and the communicator in the van have 26.620 communications capability, then use of VHF 2m on 148.150 MHz can be minimized.   Furthermore, snoopy newsies generally won't think to monitor 26.620 for the same reasons we don't use it very much: most people don't know about it!   Even if they did, most scanners can't hack the 11 meter band in which 26.620 operates.   Practical experience has shown us that if you wear a 26.620 radio on your belt, you will probably never receive incoming calls.   For some reason the human body tends to block signals in this band very well.  

    We have also found, by trial and error, that these radios don't communicate very far when used inside of vehicles.   For one thing, extending the antenna to full length is very cumbersome inside any vehicle.   Secondly, the signal does not radiate well outside of a vehicle.   If you choose to buy a TRC-235 radio, then you can utilize an external antenna.   Purchase a magnetic-mount CB antenna from any truck stop such as Love's, Flying J, Pilot, or the like.   You may or may not find the appropriate adaptor there as well--it is a PL-259 to RCA type jack.   Don't worry, though, Radio Shack has tons of these (called a "scanner adapter," Part # 278-208, $1.99).   Hook them up together and you'll be in business--simply slap the antenna on top of your car or van!  

    Another great use of 26.620 is communications training.   The limited range prevents the frequency congestion that too often occurs on 148.150.   It saves experienced communicators from severe abdominal pain when they hear a new communicator experiencing mike fright.   Any meeting night or weekend training can easily and quickly become a comm exercise.   In an Emergency Services Exercise, evaluators can use 26.260 for their communications, thus allowing privacy for exercise 'inputs,' while also allowing normal mission communications to continue.   I've heard reports of nightly 26.620 nets in urban areas; if you're close enough to your neighbors, that can easily be possible again!   Think, too, about outfitting every staff member at an encampment with a radio: the possibilities are only bounded by your imagination.

    The limited range of 26.620 MHz also means limited intereference.   During a mission, a handheld radio is often not able to talk to an operator (i.e. a ground team or aircraft) directly.   This is due to frequency congestion and/or to the limitations of range with an HT.   Because this is often true, most mission bases will have a Comm Van or similar resouce dedicated to relaying messages to and from the field.   Oftentimes GES personnel must act as "runners" from the van to the Mission Coordinator or other person who needs the message.   Having personally tried 26.620 to eliminate this problem, I have to suggest it!   The MC and Comm Van only each need a 26.620 radio.   The van filters out all the junk and the MC only hears what he or she needs to!   Furthermore, the time for a message from the MC to a field unit is reduced when the MC can call the comm van directly and doesn't further gum up 148.150 MHz.

    Lastly, 26.620 may be the least regulated (most liberal tolerances) in the coming years with regard to NTIA specifications.   This means that your 26.620 radio will probably be around to stay for quite some time--which is interesting considering that it is on one of the "older" bands in the CAP spectrum.   More on the NTIA fracas later.


    A radio that is CAP full-time may be a better choice from a legal aspect.   There are several reasons for this.   First, CAP is often considered an agency of the Federal Government when on a USAF assigned mission.   When it comes to communications, CAP is always considered an agency of the Federal government.   Thus, as a CAP communicator operating on CAP frequencies, you are subject to NTIA (National Telecommunications and Information Agency) Regulations, NOT to FCC (Federal Communications Commission) Regulations.   In other words, CAP regulations govern us within the confines of NTIA regulations.

    I want to make this abundantly clear: if you are operating on a CB frequency then you are doing so as a private citizen and can not legally conduct any Civil Air Patrol business.   In this capacity you are subject to FCC regulations.   If you are operating on a CAP frequency then you must be conducting CAP business (per CAP regs) and are acting as an agency of the Federal Government and are thus subject to NTIA regulations, not FCC ones.   Keep this in mind throughout the following legal discussion, much of which centers around the desire to operate the same radio on CAP and CB frequencies.  

    Let's look at some of those FCC Regulations (administrative law) you are subject to as a private citizen.   FCC Regulation Part 95.403, Eligibility To Use CB, states that: "You are authorized to operate a CB station unless: {A} You are a ... a federal government agency."   This precludes CAP from using ANY CB frequencies, although we generally don't need to since we have our own comm net.   This only emphasizes that there is no need to have extra CB channels installed in your radio.  

    Furthermore, it MAY not be legal to operate a CB radio that has been modified for CAP frequencies on CB frequencies.   FCC Regulation 95.409, Equipment, states that: "{A} You must use an FCC type accepted CB transmitter at your CB station.   You can identify an FCC type accepted transmitter by the 'type acceptance' label placed on it by the manufacturer. You may examine a list of type-accepted equipment at any FCC Field Office or at FCC Headquarters.   Use of a transmitter which is not FCC type-accepted voids your authority to operate the station.   {B} You must not make, or have made, any internal modifications to a type-accepted CB transmitter.   Any internal modification to a type-accepted CB transmitter cancels the type-acceptance, and use of such a transmitter voids your authority to operate the station."   The interpretation of this paragraph depends upon the definition of "modification."   Later, Part 95.425, Modifications to Transmitters, states that: {A} You must not make or have any one else make any internal modification to your CB transmitter. {B} Internal modification does NOT include: [1] Repair, or servicing of a CB station transmitter; or [2] Changing plug-in modules which were type-accepted as part of your CB transmitter {C} You must not operate a CB transmitter which has been modified by anyone in any way, including modification to operate on unauthorized frequencies or with illegal power."   My interpretation of this part says that crystals are plug-in modules that are type accepted as part of the radio.   Thus, they TYPE acceptance of the radio is not changed, but when operating on 26.620 you ARE operating outside the Citizen's Band.   Therefore, your radio and its operator must be appropriately licensed prior to and during operation on the CAP frequency 26.620 MHz.   It continues to be type accepted AND on an appropriate CB frequency when those crystals are selected.   You must interpret these FCC rules for yourself to determine your own legality when operating as a private civilian.

    As a side note, I have had some field reports of interference on 26.620 by "chicken bander" CB operators.   These are Citizens Band radio operators who illegally modify their radios for "extra channels," which really means they're operating outside of their assigned service.   Jerry Oxendine from North Carolina reports on this and that some non-crystal controlled CB radios on the market right now are easily modified for such illegal use.   Be on the lookout for these types of operations and malicious interference.

    The power limit for CB is 4 Watts.   The power limit for CAP on 26.620 with full amplitude modulation (AM) is 50W Mean Envelope Power.   The equipment that's described in this page will operate AM and will never be close to that limit.   The frequency tolerance for HF Ground Mobiles (which is what your converted radio will be) is 30 PPM (798.6 Hertz, rounded to 800 Hz or 0.8 MHz) which makes 26.6192-26.6208 MHz allowable tolerances.   If you follow these specifications, you'll be in compliance with CAP and NTIA specifications through at least the year 2008.   If you want to verify these numbers, check CAPR 100-1, page 26 and Table 10-1 on page 26.   To check the NTIA regulations, go to:   See the procedure below to find out how to determine if your radio is acceptable after you've modified it.   It may be of interest that by manufacturer's specification, the TRC-93 has a 0.005% (50 ppm) frequency tolerance and the TRC-235 has a 0.003% (30 ppm) tolerance.   An actual deviation of 50 ppm would be unacceptable but 30 ppm is the allowable limit set by NTIA and CAP National Headquarters.   This may be another reason to choose the slightly more expensive TRC-235 radio.  ITEMS REQUIRED:

    These are the items you'll need:
    Radio Shack Crystal Controlled CB Radio
    One set of Channel 10 CB Crystals (1 transmit, 1 receive)
    A #1 Phillips Head Screwdriver (common screwdriver)
    A Frequency Counter (this is an expensive piece of test equipment that your local CAP communications guru should have, or else try a commercial radio or CB shop)

    You'll need to find a crystal controlled CB radio.   The Radio Shack TRC-92 and TRC-235 are pictured to the left.   Generally, any CB radio that has less than 40 channels will be crystal controlled.   You can find these radios at ham fests, pawn shops, rummage sales, flea markets, and the like.   I've had report of people finding these radios for as little as $1.50!   Because it takes a lot of time and effort to scrounge a radio like that, however, I'd suggest simply purchasing a new one--keep it simple!   If you elect to purchase a new CB handheld radio, you have three choices.   Radio Shack offers the TRC-92 (Radio Shack part #21-1614), the TRC-93 (no part number because it is on clearance), and the TRC-235 (Radio Shack part #21-1620).   The TRC-92 is regularly priced at 19.99.   The TRC-93 is currently on clearance for $19.99; it had regularly listed for $29.95.   The TRC-235 lists for $39.99.   While the TRC-92 and 3 work fine, I prefer the TRC-235 for a number of reasons.   The TRC-235 has   significantly more features than the TRC-92 or 3.   Specifically, the TRC-235 has a squelch knob, external power port, and an external antenna port.   Furthermore, its power output is about 1 Watt versus 0.05 Watts for the TRC-92 and 0.15 Watts for the TRC-93.   These numbers are half of the specified power INPUT (2W, 0.1W, and 0.3W respectively).   This little bit of manufacturer's deception was pointed out to me by Johnathan Ohlund.   I think that the additional features of the -235 are well worth the extra $20, but if your budget truly is $30 then the TRC-93 (if you can get it) or else the TRC-92 (if you can't) may be the way to go.   The TRC-93 still works very well, and could be used to rapidly and significantly increase the communications capability of a ground team or flight line crew.   It should be noted that the TRC-92 only has one channel capability so it would be a full-time CAP-only radio.   Another cost consideration is that you can usually find a handheld 40 channel CB radio for about $50.   These radios are NOT easily modified to 26.620.   My point is that if you only want to play around with the Citizen's Band Service, then do so and leave CAP comms out of it.

    You'll need to special order the set of channel 10 crystals from Radio Shack Unlimited.   You can either do this at the store when you purchase your radio, or call 1-800-THE-SHACK.   The RSU# (part number) for CH 10 crystals is: 10045136.   They will be delivered right to your house and will take about a week.   The cost will be around $5 per set.

    The 3-channel radios (TRC-93 and TRC-235) already come with Channel 14 installed in slot A.   I wanted to add a third channel, and I personally like CH 39, RSU# 10045425, so that's what I used.




    The procedure is very straightforward.   Since every radio of the three is slightly different in how the access plates must be removed, begin by following the manufacturers instructions that came with the radio for installation of crystals.   The only difference in installation is that you are going to install the Channel 10 CB Transmit crystal in the RECEIVE (RX) slot in the radio and the Channel 10 Receive crystal in the TRANSMIT (TX) slot.   The CH 10 TX crystal should be marked in the now-familiar 26.620.   It's that easy!   Now you must ensure the unit is within tolerances.   You will have two choices for lettered channel slots on the TR-93 or TRC-235.   I use slot "C" (For C.A.P) since slot "A" is already preinstalled and would necessitate me using my soldering iron.   Some comm people who are smarter than me say the unit will work better if you realign it to 26.620 MHz, but (1) I have no idea how to do that and (2) that type of modification will almost certainly cancel the type acceptance of the radio (then you won't be able to also use CB channels with the same radio).   After you've installed the crystals, close the unit back up and find a frequency counter.   Your local ham radio expert, CAP communications expert, CB shop, or commercial radio shop will either have one or know where to find one.   Simply ask them if you radio is in tolerance for 30 ppm on 26.620 Megahertz (MHz).   I'm told that you should not use a radio that is close to these tolerances because the frequency crystal you installed will eventually drift, thus putting you out of compliance.   I'm also told that a few (about 20%) crystals will fail once they're used.   Simply purchase a new set of crystals--its a bummer, but for about $5 you still can't beat the deal.   Before you operate your radio, you will need to have it licensed through your wing's communications licensing officer.   A smart CAP member would physically bring the radio(s) to this person because he or she is likely to have a frequency counter and could finish the whole process for you in one evening.

    Special thanks to Barry and Ric for their help and information for my initial 26.620 project.

  • This page of the CAP Emergency Services Resources website was last updated 07/02/2008

    1998 - 2006 Scott E. Lanis.  All Rights Reserved.