yaseu FT-857D owners. Can you answer this?

[stevil]

I don't understand why there isn't a (legit, meeting FCC requirements) combo unit either... You can't even ask the question with out getting railed on by HAMs. I'm getting turned off by the attitude of the ham community. I'm all set to get licensed, but not sure I want to talk with anyone in my area. Especially after listening to the "rag chewing".

I have a Cobra 75wx. It's compact, cheap, can throw it in the glove box, works great for convoys on the trail, and most folks tend to have cbs if you are in the off-road community.

 

[DaveInDenver]

There isn't a combination unit because the FCC does not allow it implicitly. It's not the ham side, it's the CB side. You cannot use a non-type accepted radio on CB, which means the radio has to be submitted, tested and approved by the FCC for Part 95, which regulates CB (and FRS, GMRS). Those rules dictate that the radio can do 4W AM or 12W SSB, be channelized for the 40 CB channels, etc. The amateur rules are far less restrictive, you can use CB radios or just anything you want to modify to work. In general the FCC does not test anything ham related for type-acceptance in Part 97 (amplifiers are an exception and that's only because the FCC does not want it to be too easy to make them work on 11m). They do test commercial ham radios for general interference and compatibility, but they do that for all devices that generate RF.

The flexibility for use in ham, such as a VFO, multiple modulation modes and having more than 4W or 12W make a ham radio incompatible with CB rules. For it to even be a possibility the manufacturer would have to severely limit what the radio can do beyond the CB band and so there's no market for it when there exists millions of $50 CB that already are excellent at fulfilling the need.

The problem is once you open and mod the radio to work on ham it's no longer legal to use as a CB. I've in the past said that means it loses it's original type acceptance permanently but that is not right. You would need to have an FCC-approved licensed technician return it to original configuration at minimum, though. Ham is unique in that we can work on and build our own radios and can therefore self-certify that the radio is OK for use on the air but only on the ham bands. We are given spectrum and the FCC says have at it just as long as we practice good engineering and don't cause harmful interference outside our bands. But that privilege does not extend across all services. The FCC has licensing for people who work on radios who do have this certification authority, the GROL. There are no rules that say you can't modify or work on your own ham radios like there are with other services.

Look, hams couldn't care less if there is or isn't a combo CB/ham. The reason they don't exist is that the FCC rules are written such that they simply can not practically or economically exist. I'd probably buy one if it did exist. But since they don't hams are much more worried about losing spectrum to other services, mainly in the UHF band at the moment but that's not the only place. Plus we are being pressured in the HF bands by things like broadband-over-powerlines. So breaking the rules is not remotely in our interest with the FCC. I would like the number of amateurs to grow but the hobby is more than FM phone (FRS and GMRS exist to fill this demand as well) and I don't want to lose those other privileges in the process.

 

[kojackJKU]

No No, I agree, Im just new to the hobby, and asking questions why there is no such animal. It would be great to have one tho. I guess the 857 and my cb I have now or other small cb will be what I run.

 

[Herbie]

No No, I agree, Im just new to the hobby, and asking questions why there is no such animal. It would be great to have one tho. I guess the 857 and my cb I have now or other small cb will be what I run.

The Cobra 75WX is mentioned upthread. This + any detachable faceplate mobile HAM radio will likely be your best bet. If you don't have enough room for a second hand-mic, you need a bigger vehicle!

 

[4x4junkie]

There isn't a combination unit because the FCC does not allow it implicitly. It's not the ham side, it's the CB side. You cannot use a non-type accepted radio on CB, which means the radio has to be submitted, tested and approved by the FCC for Part 95, which regulates CB (and FRS, GMRS). Those rules dictate that the radio can do 4W AM or 12W SSB, be channelized for the 40 CB channels, etc. The amateur rules are far less restrictive, you can use CB radios or just anything you want to modify to work. In general the FCC does not test anything ham related for type-acceptance in Part 97 (amplifiers are an exception and that's only because the FCC does not want it to be too easy to make them work on 11m). They do test commercial ham radios for general interference and compatibility, but they do that for all devices that generate RF.

What in the rules forbids a type-accepted CB radio from also being usable on ham? Whether any real demand for such a unit exists or not (likely not), certainly it seems possible a manufacturer could design a radio that is full-featured on the HF ham bands, but has a button you can push which switches the radio's display from a frequency number readout to "CH - 9", and at the same time fixes the power output at 4W AM carrier, 12W PEP on SSB (FM and CW modes, and anything else not allowed for CB use simply becomes locked out in this mode). Rotating the radio's VFO knob then changes the display from "CH - 9" to "CH - 10" and so on up to "CH - 40" and then wraps to "CH - 01". Push the button again and you are now back in HF mode (CB of course now being locked out). With all the microprocessors in radios today, seems this would be easy to implement (didn't one of the newer Baofengs recently acquire part-90 certification? There's a radio that covers two services right there if so).



To those here who keep recommending small $50 CBs, remember that these are the ones that tend to create many of the difficulties that some of you complain so loudly about with CB radios (the poor-quality, muffled audio on TX often being almost unintelligible). If a $50 CB is what one desires, a Uniden PRO-510XL is about the only radio I've come across that is decent, so might as well just recommend the 510XL. For anything else, I suggest spending at least $90 or so to better your odds of having something that provides effective communication.

To the OP, I think a 510XL CB unit combined with the likes of a Yaesu FT-7900 or 8800 V/UHF unit would fit your needs well, and would keep you fully legal if that's important to you.
The 510XL is barely bigger than an 8-track tape cartridge (if you're not old enough to remember those, think maybe just a slight hair bigger than two cigarette packs laid side-by-side), which should be easy to place in most vehicles (unless those power co. repeaters you spoke of are not actually ham repeaters but part-90 (business band) repeaters, then in this case you'd be right back in the same boat again, but this time with a non-type-accepted BB radio).

Unfortunately those sound hardly any better than the cheapies, which you cannot even put a better (aftermarket) mic on one to try to improve it's sound quality. The circuit parts crammed into that tiny little metal box that is the radio's chassis are just too small, it's quality takes a big hit.

 

[DaveInDenver]

What in the rules forbids a type-accepted CB radio from also being usable on ham?

Nothing, you can use CBs, commercial radios, liberated military rigs, whatever you want in ham. But once you do any modifications to the radio it loses it's original type certification until someone re-validates it. If all it takes is software you could probably jump back and forth, such as with the Chinese Part 90 radios that some people use for ham.

It's not a ham rule that prevents it, it's the Part 95 rules that limit what radios can be used for CB.

The issue with the FT-857 is that it does not meet the rules for CB, which are specific, and thus has never been tested nor carries a Part 95 sticker. One rules is a CB radio cannot do more than 4W AM, 12W SSB. The FT-857 does 100W. That makes it ineligible for CB at the hardware level regardless if there was a firmware or software solution around it.

 

[4x4junkie]

Nothing, you can use CBs, commercial radios, liberated military rigs, whatever you want in ham. But once you do any modifications to the radio it loses it's original type certification until someone re-validates it. If all it takes is software you could probably jump back and forth, such as with the Chinese Part 90 radios that some people use for ham.

It's not a ham rule that prevents it, it's the Part 95 rules that limit what radios can be used for CB.

The issue with the FT-857 is that it does not meet the rules for CB, which are specific, and thus has never been tested nor carries a Part 95 sticker. One rules is a CB radio cannot do more than 4W AM, 12W SSB. The FT-857 does 100W. That makes it ineligible for CB at the hardware level regardless if there was a firmware or software solution around it.

It would seem perhaps you didn't read my post further than what you quoted...

That is exactly what I was talking about. You push a button on the radio and it "jumps" to CB specs (under which it would receive it's part-95 type-acceptance certification). The power output and modes of operation are fixed to CB specs, and the freq readout changes to being channelized. I don't see how what hardware the radio has would matter if the radio is incapable of exceeding the output specified by law...
Virtually every CB unit's hardware is also capable of exceeding what is lawful as well, however each radio is adjusted at the factory in such a manner so as not to exceed the law. By what amount a radio's hardware is technically capable of exceeding the law I wouldn't think is something that is specified... just that it doesn't exceed what the law dictates at it's output connector. If the radio is in HF mode, then all transmit operations on CB are blocked (like every HF radio is currently). What am I missing?

 

[DaveInDenver]

Not sure, maybe it's an interpretation. I know the FCC has taken a strong stance against 10m and 12m ham amps that were too easy to make work on CB. I can't see them liking one bit that a radio is capable of >4W carrier/12W PEP. Maybe something like a FT-817 that is a 5W radio might be easier to get approved. As it stands without the sticker there is no amount of firmware changes that make it legal and the FCC already got Yaesu to revert to hardware (zero ohm) jumpers to set configuration in the FT-857D and FT-817ND. The original non-D models could open their TX range using the programming software like in the VX-7R.

It's not that it can't be done technically or even with a certain reading of the rules. It's that precedent is that the FCC does as much as possible to make sure CB'ers can't do more damage than they already do with overdriven amps and foul language. They pursue import radios when they can, which are essentially 10m ham radios. Not one legitimate manufacturer is going to touch that can of worms if they want to keep legally importing ham and commercial radios. They don't need the headache nor the risk to their business.

http://www.ecfr.gov/cgi-bin/retriev...96fbe0f59cefcc050fa9c07&r=PART&n=47y5.0.1.1.5

Unlike ham radio where possession of a radio capable of out of band or greater than 1.5kW is not illegal, the operation is the violation, in Part 95 the possession of a radio/amp capable of TX beyond the frequencies and power of your authority is against the rules.

 

[abruzzi]

It would be great to have a radio that's detachable face, with a completely separate setup for cb and HAM band radios. you could in theory use the same antenna and the radio would do all the switching.

This wouldn't work. Antennas have to be tuned for the band they work on. Sometimes you get lucky so the 2m and 70cm bands can use the same antenna because their wavelengths are close to harmonic multiples. But an antenna for 11m would almost certainly work terribly for 2m and 70cm. Comet makes an antenna designed to work on 70, 2, 6, and 10, but they make it work by adding a bunch of loading coils, and from some of the reviews I've read if you run with all the coils it is too heavy and damages the antenna if you go over a bump. That is why all the wide band ham radios (including the 857, 897, ic7000, and others) generally have two antenna ports. One for 2/70 and the other for 6m and down. So even if you get a 857 and unrestricted the transmit, you will still have to have two antennas.

As to the discussion of why--I don't know the FCC rules verbatim, but my understanding is that the FCC is especially restrictive with CB equipment because of all the abuse in the past. They still regularly write fines when they catch store selling modified CB equipment. It may be legally possible to build a combo rig, but if that's the case, no manufacturer has tried it. So either the manufacturers don't believe it will pass type certification, or they simply don't think there is a market. I guessing the former.

So, if your interest in ham is limited to the VHF/UHF frequencies, and you want a CB, you have two options. The legal option is to buy a 2/70 ham radio with a 2/70 antenna, and buy a CB radio with a CB antenna. The technically possible, but technically illegal option is to buy an 857, modify it for out-of-band transmit, setup presets that correspond to the correct frequencies of the 40 CB band, configure those presets for AM modulation, and low power transmit (max 4 watts) run that radio to two antennas-one 2/70 and one 11m.

If you did the second option correctly, you hardware would be illegal, but your on air signal would be within spec. The reason hams tend to strongly recommend against that path is the possibility for abuse (or unintentional incorrect emissions) if we don't want the FCC (or the Canadian regulatory body for that matter) to start seeing ham radio the way the currently see CB. We don't want to get crazy certification requirements for our equipment. Right now they mostly trust hams, but if we lose that trust, our abilities will become severely curtailed. We currently sit on what is effectively many millions of dollars of spectrum they verizon or google, or someone else would love to buy.
Geof

 

[Frdmskr]

Sorry I have not replied sooner.

I would do this. For V/UHF ham Radio (most often used for overlanding) mount the V/UHF antenna at the hood of the Jeep. There are lots of pictures of, and mounts for, this. I would then look at a Breedlove mount for the rear quarter panel on the opposite side of your Jeep from your gas tank. This mount is a 3/8"x 24 mount. It will handle a CB antenna and an HF ham antenna.

When overlanding you will use one or the other. Consider a 102" whip for CB with a spring at the base. This will give you something that will not break. It can also be loaded on 10m (techs can use 10m below 28.500 MHz). You can then determine which radio will get plugged into that antenna based on what you are doing. I'd recommend manually swapping wires. Less loss and less to break.

As you get more privledges you can get other antennas for the rest of HF. Screwdriver antennas are best.

Also, spend some time with http://www.k0bg.com.

Good luck studying for your test! Hope to work you one day!

 

[vicali]

The reason hams tend to strongly recommend against that path is the possibility for abuse (or unintentional incorrect emissions) if we don't want the FCC (or the Canadian regulatory body for that matter) to start seeing ham radio the way the currently see CB. We don't want to get crazy certification requirements for our equipment. Right now they mostly trust hams, but if we lose that trust, our abilities will become severely curtailed. We currently sit on what is effectively many millions of dollars of spectrum they verizon or google, or someone else would love to buy.
Geof

^exactly
I ran a CB for 8 years in the previous rig, I've had more useful convos/info in the last 4 months of HAM than I ever heard on CB.
Run both if you want both, but I can't see why you would.

 

[stevil]

Thanks for all the thoughtful contributions to this thread. I've asked this question elsewhere and never been able to get a useful answer.

 

[4x4junkie]

http://www.ecfr.gov/cgi-bin/retriev...96fbe0f59cefcc050fa9c07&r=PART&n=47y5.0.1.1.5

Well, I did find this buried in that link:

§95.655 Frequency capability.

(a) No transmitter will be certificated for use in the CB service if it is equipped with a frequency capability not listed in §95.625, and no transmitter will be certificated for use in the GMRS if it is equipped with a frequency capability not listed in §95.621, unless such transmitter is also certificated for use in another radio service for which the frequency is authorized and for which certification is also required. (Transmitters with frequency capability for the Amateur Radio Services and Military Affiliate Radio System will not be certificated.)

So I guess that puts to rest such a unit being legally possible.
Leave it to the government to require you to install and juggle two technically redundant radios.


I also found this (pertaining to your comment about being in possession of non-type-accepted gear):

§95.411 (CB Rule 11) May I use power amplifiers?

(a) You may not attach the following items (power amplifiers) to your certificated CB transmitter in any way:

(1) External radio frequency (RF) power amplifiers (sometimes called linears or linear amplifiers); or

(2) Any other devices which, when used with a radio transmitter as a signal source, are capable of amplifying the signal.

(b) There are no exceptions to this rule and use of a power amplifier voids your authority to operate the station.

(c) The FCC will presume you have used a linear or other external RF power amplifier if—

(1) It is in your possession or on your premises; and

(2) There is other evidence that you have operated your CB station with more power than allowed by CB Rule 10, §95.410.

(d) Paragraph (c) of this section does not apply if you hold a license in another radio service which allows you to operate an external RF power amplifier.

I read that as the simple possession of an amplifier isn't necessarily a violation, there would have to be other evidence that you have actually used it (probably would consist of multiple complaints of interference and/or an observed field-strength measurement). It doesn't make mention of radios that have out-of-band frequency capabilities, though I would think such would be treated in the same manner (which someone operating out-of-band is something quite easy to observe, much more so than someone using non-type-accepted radio gear that produces a signal that otherwise meets specification (which I would also agree that if you did modify a non-type accepted radio to work on CB, but were careful to make sure your over-the-air signal was within limits, no one would probably ever be the wiser).

There was a comment made earlier though about an 857 not being designed for CB that I do have to back up... Radios like the 857 tend to be EXTREMELY hypersensitive about mic level adjustment in order to not sound garbled on CB (AM), making it unlikely it will work well in a mobile environment. Standard CB units that use a high-level modulation circuit in the final PA stage are not susceptible to garbling in the same way the low-level circuit in a 857 would be (and to top that off CB units also have built-in modulation limiters to further reduce distortion that would otherwise be caused by overmodulation).
So unless the 857 has a speech processor built into it that works at the transmitter's audio-input stage (like the one on the older FT-757 for example), you would likely have to add an external audio processor or limiter plugged inline with your microphone to keep garbling under control as driving conditions change in your vehicle (removing much of the advantage of having CB and ham combined in the same rig).

 

[DaveInDenver]

I have to admit I've used my FT-857 maybe a handful of times on AM, mostly just to see if it works. The majority of AM is listening, broadcast stations, air band.

The FT-857 uses a dynamic mic out of the box (MH-31), which is pretty similar to stock CB mic, which is to say a dull but effective response. The radio has a couple of transmit side options: AM-specific mic gain, adjustable compression, an AF low and high pass filter. It's also possible to tweak the AM mode carrier level in the service menu without opening the radio, which can help.

Yeah, the ALC is pretty aggressive on these radios and tends to flat top on AM. It's compounded with any mismatch (reflected power will drive the ALC into action) in the antenna, something that's hardly rare in mobile situation. The radio is designed to work well at mobile SSB and FM, not AM so much. It works alright but won't be mistaken for an Orion on the air even working well. It's an effective and small mobile communications rig, not a hi-fi ragchewer. Design criteria are different.

For the question at hand it would probably work fine despite being a low level (early) modulator at low power AM because where you run into trouble with the FT-857 is when you try and drive too much carrier power. At 4W carrier the radio would have something like 18dB of output headroom, so it would be very unlikely to downward modulate. You find problems when using the full power, e.g. trying to get a decent signal at 25W carrier with the mic gain set to push the limit of the PA.

However, it's also easy to get a terrible signal on SSB with the radio for the same reasons (too much mic gain causing the ALC to become aggressive), so I'm not sure it's really unique to AM just more apparent. One nice thing about radios like the FT-857 is that you can monitor the ALC so it's much easier to set the gain and compression to prevent distortion and spatter. My old Uniden has no way to monitor or set mic gain, so you're at the mercy of whomever was the last person to tune the radio.

 

[4x4junkie]

I wanted to avoid getting too technical in my last post, but what I have always seen in transistorized HF amateur radios is that such radios derive their AM carrier from the SSB balanced-modulator circuit (biasing it off-balance slightly so that some amount of carrier can pass through it). The problem with this method arises vividly if 100% modulation is ever exceeded (even by just a tiny amount). Instead of simply clipping, the signal rapidly morphs into a double-sideband reduced-carrier emission (the sidebands become stronger than the carrier itself). This results in the signal being garbled because it cannot be demodulated properly by a standard AM receiver (on a SSB receiver, you can still tune the signal in on either sideband and it will be fully intelligible). The problem is compounded by the lack of any sort of modulation limiter to prevent the radio from overmodulating in the first place (ALC is ineffective against overmodulation, ALC's primary purpose is to regulate the power output of the PA stage).

With a CB unit (which most frequently uses some method of directly modulating the voltage supply to the final PA transistor), it's not possible for the signal to morph into a DSB-reduced-carrier emission should 100% modulation be exceeded, instead you end up with ordinary clipping of the signal (flat-topping & bottoming), which will still demodulate correctly in a standard AM receiver. Of course clipping increases a signal's bandwidth exponentially, which is why manufacturers of CB units also incorporate a modulation limiter circuit into the radio to reduce clipping to a minimum (it effectively works as an automatic mic gain control). If HF radios had something similar to hold the modulation to 100%, it might work on them just as well, though I have yet to see anything of the sort on a HF rig.
Admittedly I've been somewhat out of the loop on HF rigs for the last decade or so... if someone has actually implemented one during that time, then that would be great. However I suspect the AM mode on these rigs is something most manufacturers don't put much emphasis on simply due to it's lack of popularity on the ham bands. I suspect it exists in the radio for no other purpose than to allow them to market it as an "All-Mode" radio.


As for monitoring your signal on your Uniden, it's quite easy if you have a simple peak-reading wattmeter... All you need is to monitor how much the meter swings up when you speak into the mic (usually it'll be an indication somewhere around 10-12 watts PEP from a 4 watt carrier on most meters).
Where it's much harder to monitor your audio is on most any FM rig because there's nothing at all there that a wattmeter (nor even a 'scope) can show (and most FM rigs have wide-open modulation circuits without any mod meters or indicators whatsoever). You typically have to turn on another radio like a HT and then listen to yourself on it to know how you sound.