VHF vs CB handhelds

Log Out | Topics | Search Moderators | Register | Edit Profile

Thread Last Poster Posts Pages Last Post   Closed: New threads not accepted on this page

Author Message   Chris Merritt (Smokinbro) Posted on Thursday, March 14, 2002 - 03:44 pm:    Looking for a little advice on VHS vs. CB radios. Do VHF radios also transmit/receive CB frequencies? I do a little off-roading and sailing as well. I'd like to get a handheld VHF to carry with me when sailing (I charter and don't neccessarily trust the on-board equipment) but figure that the VHF coudl be useful when out in the bush as well. Anybody have any experience with this?   Axel Haakonsen (Axel) Posted on Thursday, March 14, 2002 - 04:28 pm:    CB Frequencies VHF Frequencies So I suppose the answer is a definite maybe. There probably are radios in existence that will transmit on both bands, but I don't know how to go about finding one.   DaveB Posted on Thursday, March 14, 2002 - 04:38 pm:    Chris, Marine VHF radios and CB's are completely different animals. A real apple to oranges comparison. CB's operate in the HF radio spectrum at 27MHz and use Amplidute Modulation (AM) or Upper/Lower Single Side Band suppressed carrier modulation (USB or LSB). Marine VHF radios oparate around 156MHz and use Frequency Modulation (FM). The Marine VHF radios have many tachnical advantages over your everyday off-the-shelf CB, however it is illegal to use a Marine VHF radio for non-marine purposes. The FCC does not bother with much enforcement in the CB band, you don't even need any licence to operate a CB. Marine radios are very different, they must be licenced to a specific vessel and you must identify yourself with your licence callsign when using a marine radio. Believe me, the FCC nails people illegaly using marine radios every week. Go to the FCC web site at www.fcc.gov and look at the postings from their enforcement logs. If you need an inexpensive walk about radio for short range point to point comunication, the new Family Service Radios (FSR) offer a legal comprimise. Another ultimate solution for off-roading would be to get a ham radio licence and a ham rig. Anyway, that's my long winded 2 cents worth on the subject. Dave   DaveB Posted on Thursday, March 14, 2002 - 04:44 pm:    Axel, An easily modified Icom 706MIIG HF/VHF/UHF ham rig can be programmed to do just as you suggest. However, the radio is not certified for use on anything other then use on amateur radio bands, thus it would be illegal to use one for either CB or Marine VHF use. Dave   eburrows Posted on Thursday, March 14, 2002 - 04:56 pm:    Not exactly. If you'r ham rig can do less than 4 watts of power, then you can use the CB band, and other 'citizens bands' like MURS and maybe GMRS. You just need to be carefull not to put out too much power, and use only the designated channel frequencies. One band ham radios definitely cannot use legally, is the FRS band, as the FCC has very strict regs on exactly what kind of radios can use it. Nevertheless, my Yaesu FT-817 does CB, some MURS, GMRS, FRS, some marine, and nearly all ham bands just fine. CB is great, 27 Mhz is very low, and 4 watts is decent power for caravan-type communication. The problem with it is that it is so crowded! In southern california, I can hear three or four conversations on every channel all the time! FRS sounds really good, being FM instead of AM or SSB, but it's range is very limited. The ham bands are really the way to go, but not many off-roaders use it. Look at it this way: A hand-held (HT) CB radio is probably ~$100. A FRS HT is ~$40. My FT-817 was $800. Just get the two HT's.   Chris Merritt (Smokinbro) Posted on Thursday, March 14, 2002 - 07:45 pm:    Thanks guys. I was aware of the requirements for licences for VHF - and if I go this route, I would definitely get my operator license. My desire for a VHF is for near-shore sailing. In our waters, a backup VHF set is cheap insurance. I had only hoped that it would also be practical for off-roading as well. As it isn't, I will just get two sets - one for the water, one for the dirt   joel Posted on Friday, March 15, 2002 - 12:41 am:    Get a radio with freq. that others use in case you need help. Having said this, a VHF handheld will be much more compact and antenna efficient than a CB handheld due to the antenna required. Here in South Africa the offroad fraternity use 29Mhz for offroad which is neither CB or VHF.   Curtis Posted on Friday, March 15, 2002 - 02:27 am:    The Icom 706 (any version) is the way to go. It can be "opened up" by removing or crushing a simple transitor. You have to watch it though. I have heard stories of guys accedentally blasting at 100W on Airport , cell blocked, and mil freq's. The FCC nor FAA likes that. It is highly illegal. Once opened up the 706 can transmit up to 100W on 70cm to 6M in AM/FM/SSB/CW. The cool thing is that in an emergency you could get on a CB freq and ask for help if needed. You do not want to use it for regular CB talk as I think it only goes down to 8W. The Icom is not a handheld, but a mobile. It is about the size of the old CB's, but has a removable faceplate with an optional faceplate extension cord so it can take up as little space as possible in your rig. You can also get extra mount kits to move it around. Not that I know anything about the 706 though. Also - look at the Yaesu VX-5R 70cm/2M/6M handheld. Max 5W so not much more powerful than CB, but it is small and less than 1/2 the price ($350 I think) Curtis   Paul T. Schram (Paulschram) Posted on Friday, March 15, 2002 - 10:14 am:    The use of a modified amateur radio transceiver outside of its "Type Accepted" frequency range is unlawful. It used to be that any work on a CB required the technician to hold a commercial radio operator's license. For what it's worth, the Kenwood rigs can operate on extended frequencies by user accessible menu operations. The comment about South Africans using 29 MHZ is very likely in violation of ITU rules as this is a ham band, requiring licensing. Given the appropriate solar conditions, 11 Meters can be a very effective long range communications medium using low power. I have a Yaesu FT-7, 10 watts 80-10 meters which at times of solar cycle peaks has been a wonderful long distance rig. I have literally worked the world using ten watts on ten meters mobile. I have just recently received a mail confirmation of a conversation with a gentleman in South Africa on 20 meters from my Disco. Now, for the real kicker, the FCC has begun very aggressivley enforcing all of the regulations related to radio communications, confiscating equipment, suspending and revoking licenses and imposing strict monetary penalties to those who have been caught. As these are civil cases (in most cases), the fines are imposed without court appearances. Get your ham license. Go to www.arrl.org for info. Paul WD9HRP Extra class long before April 15!   Mark & Bev Preston (Markp) Posted on Friday, March 15, 2002 - 11:26 am:    I agree with Paul. Get your amateur license. The local Binder club here in Colorado has gone to 2 meters for trail and local 'rag-chewing'. A few have wondered why they didn't do it before and have commented that CB sucks compared to amateur. In addition to better simplex, you get repeaters and the opportunity to work long distances with HF. Find your local ham club. They will offer evening classes. Technician class is not that hard. Mark KC0MAB   Curtis Posted on Friday, March 15, 2002 - 12:40 pm:    I agree with Paul & Mark - Get your license. It is an easy test for Technician that I bet most could pass with a day or two of study. Mark, it is great to hear that you have a club using 2M. I think it should be the standard for any 4X4 organization. As far as the legality goes, Paul is right on. However, I believe that these rules get thrown out the window if you are in a life or death situation. In this case I think you can transmit on almost any frequency with or without a license. I would refer to the FCC rules & regs though before you believe me or anyone else. It is also important to note that you can listen in on legal frequencies without a license. This includes a much wider range than you can transmit on with most licenses. I know I do much more listening than talking and my radio is primarily used for emegencies in the bush. Curtis KD7MMK   Curtis Posted on Friday, March 15, 2002 - 12:51 pm:    Here is some reading if one is interested in emergency communications and the FCC regs. This is from: http://wireless.fcc.gov/services/amateur/about/communications.html#s7 It outlines the rules for Ops in Energencies and then outlines that the rules do not prevent transmission or use in the events or distress or protection of lersons or property. __________________________________________________ Operations in Emergencies Q. Is it correct that my station must not transmit analog voice emissions on the HF band digital emission segments even during an emergency? A. Yes. The Rules, including the analog/digital emission exclusive segments, are carefully designed to provide an amateur radio service in the United States that has certain fundamental purposes. Section 97.1 declares that the foremost purpose is expressed in the principle of recognition and enhancement of the value of the amateur service to the public as a voluntary, noncommercial communication service, particularly with respect to providing emergency communications. It would be illogical to abandon these Rules -- which are carefully developed through the rule making process with the input of amateur operators and organizations experienced in providing emergency communications -- during an event of the very type for which the Rules were intended. Q. Are there exceptions? A. Yes. There are two exceptions. In summary: Section 97.403 states that no provision of the Rules prevents the use by an amateur station of any means of radiocommunication at its disposal to provide essential communications in connection with the immediate safety of human life and immediate protection of property when normal communication systems are not available. Section 97.405 states that no provision of the Rulesprevents the use by an amateur station in distress of any means at its disposal to attract attention, make known its condition and location, and obtain assistance. A sinking ship is a good example. It further states that no provision of the Rules prevents the use by a station, in that exceptional circumstance, of any means of radiocommunications at its disposal to assist a station in distress.   Chris Merritt (Smokinbro) Posted on Friday, March 15, 2002 - 01:17 pm:    This is excellent information! Thanks to everyone. I appears that I will require the VHF for marine use (as most reasonable sized craft have a VHF set and in an emergency you want to be using what everybody else does - NO?) For the bush then I will just go ahead and decide on FRS or CB. Again, thanks to everyone who provided the excellent technical comments and links!!!   Curtis Posted on Friday, March 15, 2002 - 01:46 pm:    Chris, One note: CB is only useful in the bush for very short distances. It has the advantage of being common since there is no license required. They are very weak though and are not a means of summoning reliable emergency assitance. You can get a basic single band (2M) or dual band (70cm/2M) for very little money. $100 to $150 for many basic mobile units. I would highly reccomend getting a dual band to augment your CB. FRS/GMRS is better than CB and even though there are more users, it is still limited as an emergency tool. Getting a license is only a license to transmit under normal operating conditions. I do suggest every wheeler get one, but I know plenty that don't and keep the radio up just for listening and emergencies. Just a thought. I don't like the idea of people getting screwed in the wild. I spend too much time there to risk it with no comm. Curtis KD7MMK   Leslie N. Bright (Leslie) Posted on Friday, March 15, 2002 - 02:00 pm:    IMHO, It depends on what "the bush" is for you. If you're in Australia, or the Amazon, or the Mojave, or parts of Montana, or...... then range is a VERY critical issue. If "the bush" for you is the southern-central Appalachians, then odds are you'll be w/in "earshot" of someone on a CB. There are places I could go to get out far enough, sure, but it's not far to get back w/in range in those places, and they're few and far between.... too many interstates and primary highways. Shoot, I can be in the middle of nowhere here in southwestern Virginia and pick up coal-mine haul trucks from almost anywhere. FWIW, YMMV.... -L   Paul T. Schram (Paulschram) Posted on Friday, March 15, 2002 - 03:15 pm:    WOW! This question sure brought out the radio nerds! And no comments about guns or music. Strange. BTW-I pack a .38 spl revolver and listen primarily to the Grateful Dead. When I'm not on 20 meters working DX! There, that ought to bring the thread back to life again:-) peace, Paul   Leslie N. Bright (Leslie) Posted on Friday, March 15, 2002 - 03:36 pm:    Come hear Uncle John's Band, playing to the tide Come with me or go alone He's come to take his children home LOL..... .45 -L   Curtis Posted on Friday, March 15, 2002 - 03:50 pm:    hehe. USP.40 Compact while listening to the soft ballads of Fred Durst or some other such degenerate CB's just plain suck. On a good day I can throw a rock further than many CB's can transmit. I find it humorous when the guy at the back of the line can barely transmit to the front cause there are a few trees or rocks in the way. I own and use a CB, but would never rely on it. Another poster & I were in Moab in Oct. We both had CB's and Hams. CB's were good for line of sight at about the distance of vision. We talked on the HAM's for several miles off at low power and up and over hills and all kinds of stuff. HAM radios are still technically "line of sight", but there are some neat things you can do with 50W-100W Curtis   p m Posted on Friday, March 15, 2002 - 03:51 pm:    FWIW, on AM CB, FCC limits power to 4W, which leaves about 1W for the sidebands (where information is carried). And that's split between 2 sidebands which carry the same information. For SSB transmission, FCC's limit is 12W PEP (peak envelope power), so you gain a lot right there if you buy a SSB-capable CB rig. There's more rambling about the compound benefits of SSB vs AM transmission given equal power, but I'll leave it out. Peter   Leslie N. Bright (Leslie) Posted on Friday, March 15, 2002 - 03:55 pm:    Peter, I'm not a techie (well, at least in wireless communications), so this may seem like an odd question, but.... Can a SSB-CB communicate w/ an AM CB?? -L   Chris Merritt (Smokinbro) Posted on Friday, March 15, 2002 - 03:59 pm:    Just to give you an idea - I live in B.C. and often use logging and mining access roads and Forestry trails as short-cuts on some of my business trips. (often seems to take 4 times as long as the regular route). I will have to investigate what the loggers and miners use for communication.   p m Posted on Friday, March 15, 2002 - 04:00 pm:    Nope you need someone else with an SSB rig (like me peter   Curtis Posted on Friday, March 15, 2002 - 04:03 pm:    peter - that is irrelevant if you are not armed   Chris Merritt (Smokinbro) Posted on Friday, March 15, 2002 - 04:04 pm:    Curtis - you suggested "You can get a basic single band (2M) or dual band (70cm/2M) for very little money. $100 to $150 for many basic mobile units." As I am not tranceiver proficient - is this 'short wave' in layman's terms? Would a unit such as this transmit in the VHF marine bands? Sorry if the questions are too basic - just want to learn the 'geography' before I talk with a salesperson.   Curtis Posted on Friday, March 15, 2002 - 04:14 pm:    Chris, I do not know the exact freq's for marine. I am pretty sure they are different, but exactly what is different escapes me. If someone else does not chime in with the answer I will try to look it up for you tonight. Curtis   Paul T. Schram (Paulschram) Posted on Friday, March 15, 2002 - 04:21 pm:    Curtis, Line of Sight propagation is directly related to the frequency one is using. The MUF or maximum usable frequency is determined by among other things, ionospheric activity which is typically controlled by solar flares pumping ions into the atmosphere (or vacuum, more correctly). To make matters worse, some frequencies are absorbed by such things as water in the air (OK, for this, you have to be at or near visible wavelengths, but the theory is the same). When you go up in wavelength (to a limit), the RF will bounce back from the atmosphere. At lower wavelengths, the RF will either go right out through the atmosphere, or be absorbed by it. Things get much more difficult to explain during periods of meteorological extremes, such as stratification (layers of different temperatures of air), result in the "Ducting" of RF, thereby giving you great distance with frequencies one would not expect to achieve such propagation. I have had great fun working Auroral propagation while at my camp in Michigan's Upper Peninsula during the Aurora Borealis. Comets and meteor showers are cool too as the ionization trails cause short windows of long distance propagation at many frequencies. Usually, if your frequency is above 50 MHZ, it will closely approximate line of sight. Below 50 MHZ, unless you are in a situation where NIVS (near incident vertical skywave) is predominant, you will not be able to talk to someone nearby, but can very distant. In some cases, you are unable to hear one another on CB because your RF is going very far away, in effect, skipping right over your intended recipient. In other situations, the polarization of your antennas may become involved to hamper or assist propagation and readability. PM: I was wondering when you'd chime in:-). Leslie: When life looks like Easy Street... Maybe we should do a Field Day run out to Moab or somewhere similar. That would be something, wouldn't that be something (now that's an obscure Dead tune!). Peace, Paul WD9HRP   Leslie N. Bright (Leslie) Posted on Friday, March 15, 2002 - 04:23 pm:    Ah.... SO, to be able to communicate w/ most other people around, you have to stick w/ AM -CB... right? SO, do you have two CBs in the Rangie?? OR are they in the Wag? BTW, how's Timex?? Doc have it running yet? -L   Curtis Posted on Friday, March 15, 2002 - 04:40 pm:    Damn Paul, You just wrote more about line of sight and atmospheric ducting than a Tech licensee like me will ever know. Thanks for the info as it cleared up some stuff for me. CB's still suck though I am all over a Moab trip. I live about 3.5 hours away and have not been down since Oct. I'm just itching for a reason. I am thinking the 1st weekend in April - anyone? Curtis Curtis KD7MMK   Curtis Posted on Friday, March 15, 2002 - 04:42 pm:    pm - good to see you back. You did not happen to stop off in Hawaii on the way to Samoa did you? Some kind of oceanographers conferrence there. Damn tourists. Curtis   DaveB Posted on Friday, March 15, 2002 - 04:47 pm:    Paul, Great comments above! So are we talking CQ field day Moab?? I have a DX mobile D1! All dressed up with a 706, auto tuner, dual batteries and ready for a radio party! Although, Moab is a little far away for me, I was thinking of mountain topping somewhere in the Sierra since I live in the SF Bay Area. Chris, Here's some more to add to what Paul stated- The Marine VHF band in centered around 156MHz. The marine weather channels range from 162.40MHz to 162.55Mhz. Here are a few voice channels: 13=156.65MHz, 16=156.80MHz, 72=156.625MHz. You can look up the exact frequencies for other channels on numerous webs sites. The 2 meter ham band runs from 144Mhz - 148MHz the 70cm ham band runs from 420MHz to 450MHz, but the FM voice protion of interest runs from 440MHz to 450MHz. You can break down HF/VHF/UHF as follows: HF - 3MHz to 30MHz VHF - 30MHz to 300MHz UHF - 300MHz to 3GHz This is a somewhat loose definition, but most RF text books break it down as listed. The point is to break away from the thinking of Marine VHF, CB, FRS etc... They are just names for different communtcation services. You need to look at the frequency of transmission and reception and what type of modulation is being used to tell if one radio will be compatible to communicate with another. Since the Marine radios operate at 156MHz they are refered to as "Marine VHF" radios. The 2M (144MHz) ham band is also VHF, but at a slightly lower frequency. This is a great thread... Radio geeks unite... except I have to get back to work now... Dave WD6EBC   p m Posted on Friday, March 15, 2002 - 05:06 pm:    hehe Leslie, too many Qs now, i don't think Doc fixed Timex; i didn't follow up closely on that matter i've met a (probably one) NZ FSJ owner - Chris Medicott - in Lyttelton, NZ. Very cool fella! my SSB CB rig is floating between the disco and rangie, the big yellow Cherokee sports a dinky $45 Cobra deal (somehow it is the best-tuned rig, the CB that is). Now that I've got myself a brand new 4' firestik instead of beat and bent old 4'.... Curtis - no, i only stopped in HI on my way back from WS to mainland. there was indeed Ocean Sciences Meeting in Honolulu, my name may have even been mentioned there. Like, once.... i posted some photos - click here Paul - I meant to say the same about you peter   Chris Merritt (Smokinbro) Posted on Friday, March 15, 2002 - 05:07 pm:    DaveB - this is exactly this stuff I had hoped someone would chme in with! So if I've got it 2M HAM band = 144 - 148 MHz. "Marine VHF" = centered on 156 MHz. Are there portable or handheld HAM transceivers that operating from 144 - > 156? I.e. Could I write the appropriate exam - pay the fee and get a HAM license then buy one (1) tranceiver for both my expensive sailing habit and my expensive LandRover habit?   Mark & Bev Preston (Markp) Posted on Friday, March 15, 2002 - 05:14 pm:    Nice rig Dave, I mean D1. I'm in Colorado so does that mean line-of-sight Sierra to Colorado Rockies :-) So what do you think of the Yaesu FT-100D? Yaesu is offering a $200 off coupon till March 31st. Basically the same price as the 706 except it comes with the filters. Now if I could just find the $1K. Mark KC0MAB   Curtis Posted on Friday, March 15, 2002 - 05:16 pm:    pm - good shots. I would be remiss if I did not reciprocate: http://www.newkirks.net/images/hawaii2002/index.htm Fantastic part of the world, is it not? Chris - I think there are some transcievers that can be opened up even past that range. Again - if no one pipes up I will look it up later. No dice on the license though. Ya gotta go take the test. It is quick and easy. Curtis   Curtis Posted on Friday, March 15, 2002 - 05:21 pm:    Mark, I hear about a lot of problems with the FT-100 right out of the box. Go with the 706. I had one for a while and it was a great unit. Sold it only because I was more interested in APRS & Packet Radio than HF. Got a Kenwood TM-D700A and cannot say enough good things about it. Curtis KD7MMK   DaveB Posted on Friday, March 15, 2002 - 06:21 pm:    Chris- There's a bunch of 2m/70m ham hand helds available. There's even ones that are tri-band and quad-band. Some a big, some are really small, etc. It's hard to keep up with what's out there unless you are in the market to buy. It's best to drop into a ham supply store and check them out to see what you like. Icom, Kenwood and Yeasu all make good stuff. As for getting your licence, a local ham store usually has info for local ham clubs that run licence classes and test sessions. You can also check on-line for local club info at www.arrl.org Mark, I checked out both the FT-100D and the IC-706MIIG. I liked the 706 better, it was easiler to use, larger display, the buttons were in the right place for me, etc. A friend of mine who is a hard core DX'er has an FT-100D and likes it allot. The FT-100D does have better DSP functions if that is important to you. I would go to a ham shop and check both rigs out and see what you like better. I am lucky, spoilt or cursed depending on how you look at it, but my office is two blocks away from a Ham Radio Outlet store here in silicon valley. I go there for a short lunch hour walk and check on the latest goodies. I'm running a 706MIIG with the AH-4 tuner mounted in the rear storage box feeding a 20M ham stick mounted on the rear bumper. It works well for 40M to 6M. I have a 2nd 2m/70cm dual band antenna to the two top bands. To reduce this to total radio geekdom I can post pictures upon request. Dave WD6EBC   Mark & Bev Preston (Markp) Posted on Friday, March 15, 2002 - 06:55 pm:    Thanks Curtis and Dave, Had heard that the FT-100 has some early issues but that the FT-100D has solved them. I'll have the check out the Kenwood TM-D700A. Would love to see some pictures Dave. I've been thinking about where to put the equipment when considering water crossings. I know, seal it up. Mark   DaveB Posted on Friday, March 15, 2002 - 07:27 pm:    Mark, Here's a few shots I have on hand. I can email more detailed stuff if you want, since I'd have to take photo's tomorrow. ***WARNING*** The following photos depict graphic ham radio geek porn Dave WD6EBC   DaveB Posted on Friday, March 15, 2002 - 07:31 pm:    Opps, sorry, the photo's would not load. The message board wont let you load picture files larger then 50k. Either that or radio porn is just to horrible graphic for this message board. Dave   p m Posted on Friday, March 15, 2002 - 07:33 pm:    Curtis, some awesome shots there! peter