Is using a vfo in AM/SSB modes in the 27 mhz band legal? say 27.385 is too busy can one legally move to 27.380 or 27.390 to avoid the heavy traffic to make contacts? thanks in advance.
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Is it legal?
- Thread starter mackmobile43
- Start date
no its not legal in the states,and was also the reason the fcc withdrew the ability to get radios with kc shift/coarse/tx/rx tunes certified too,hence the reason why all legal US sets with ssb only have clarifiers/rx only tuning.
Ah I see and that makes sense in one respect but for efficient use of the band it makes no sense whatsoever.
And would that make use of any hf rig in the 27 mhz band illegal sense only type accepted units there are allowed for cb users knowing that amateur rigs do not have to have Fcc type acceptance?
And would that make use of any hf rig in the 27 mhz band illegal sense only type accepted units there are allowed for cb users knowing that amateur rigs do not have to have Fcc type acceptance?
Unless your part of a M.A.R.S. group its illegal according to the FCC rules. Also there is the issue of power everyone knows that most most radios are set at around 4 watts at the manufacture but I personally have seen a few that came off the line at a bit more.
Most HF rigs will receive on 11 meters but will not transmit without the known modifications. Now my question is what are these delta tune oe fine tune knobs on some of the older CB radios was that the same as a cl;arifier but with just a slight adjustment capability?
Most HF rigs will receive on 11 meters but will not transmit without the known modifications. Now my question is what are these delta tune oe fine tune knobs on some of the older CB radios was that the same as a cl;arifier but with just a slight adjustment capability?
Back in the 23 channel days they built them so the tx and rx would shift just a little, and FCC type accepted them that way.
When they went to the 40 channel rigs in Jan of 1977, FCC changed to rule to only let the rx slide a little bit and the tx had to stay locked.
Check this out for a good read.....CB History
73
Jeff
Voice lock on cobra radios is yet another way of saying the same thing,its just a manufacturing ploy to make the uninitiated buyer think he's getting something more special than other radios offer.
Same goes for mic gain,which is really a mic attenuator or rf gain which is really a rf attenuator as well,gain makes them sound lke they improve tx audio or improve incoming signals when the reality is they do the exact opposite.both are again manufacturing ploys to make you think you got controls that add to the radios performance,when in reality they detract from it.
Cb radio manufacturers have long taken advantage of peoples ignorance,whether it be controls on radios that do the opposite that they are suggesting,or antennas with fake Db gain claims or linears with overrated input/output claims.Another common ploy is changing the aesthetics of radios but having the exact same circuitry,then charging a premium for a particular brand name,which is no better or worse than competitors radios with the same chassis.
As audio shockwave correctly says in the old days manufacturers were allowed to fit tx shift on radios as the stability of radios back then wasn't that great,but when they tightened up the specs for pll 40ch sets,there really was no need for tx shift as pll radios are generally pretty stable and are allowed a certain amount of leeway either side of the wanted frequency and still be considered on frequency.they also tightened up specs on harmonic generation/radiation too.
Rx shift/clarifier/fine tune whatever you want to call it is still allowed on ssb radios due to the nature of ssb,and its need for exact frequency tuning for audio to be resolved clearly,not to mention the fact that because of the stability leeway given to ssb transmitters no two ssb radios will ever be on exactly the same frequency.
A sure sign a radio is export/illegal spec is the inclusion of a coarse shift/tune.
Efficient use of the cb band isn't a consideration,its more down to governments who like to dictate things.Common sense isn't a factor governments are noted for.
Hate to disillusion you, but there was never any 'user' changes in transmit frequency allowed by the FCC. No transmitter VFOs, no unlocked clarifiers, etc. 'RIT' yes, 'XIT' no. Anyone who tells you differently is mistaken.
- 'Doc
And about that type acceptance thingy for ham gear. If it's sold commercially in the USA it has to be type accepted (or whatever it's called now), even the kits. If a ham wants to build or modify something to use on the ham bands he/she can do so without that type acceptance, but it has to meet standards. set by the FCC.
- 'Doc
And about that type acceptance thingy for ham gear. If it's sold commercially in the USA it has to be type accepted (or whatever it's called now), even the kits. If a ham wants to build or modify something to use on the ham bands he/she can do so without that type acceptance, but it has to meet standards. set by the FCC.
I was familar with voice lock but the delta tune was the one that I wondered about although I kind of figured it was the same thing.I have alot of radios laying around in closets and in my outside building and I never hooked one with (Delta Tune up to a frequency counter to look at how far they would slide either way. Thanks for clearing this up Audioshockster.
FYI, the Greek letter Delta, which looks like a triangle, actually means "change". That is why some fancy assed radio designers called the fine tuning control a Delta Tune because it meant a change in tuning. Some radio even had a small triangle before the word TUNE.
Hate to disagree with you Doc. but the older 23 channel CB's did in fact have an unlocked clarifier that would move about 800-1000 Hz. maybe a tad more. That was a user adjustable control. I suppose the range was just enough to fall within the old frequency tolerance limits but nevertheless it was user control over the actual TX frequency albeit to a limited degree.
So I was correct in saying it was just a slight adjustment that could be made. I know Ive messed with a radio that had that and didnt see a whole lotta change if any at all. Although AM is so wide banded that it would take a huge adjustment to really see that somethings happening.
My Browning Mark III has a clarifier on the transmitter as well as the receiver. Stock from the factory the transmitter can shift plus or minus several hundred cycles. This was allowed before 40 channel PLL sets. VFO transmit was not allowed and why the early tram D-201 still had receive only VFO.
My Midland 13-898B also had the clarifier shift the TX as well as the RX straight from the factory.
DOC, I know the years are sliding by...but yes many of the 23 channel set`s had a Delta tune/fine tune/voice lock that shifted tx and rx, my 23 channel Midland 13-895 did it right out of the box.
Its ok tho...i still think you are a good guy even for a C.O.B
73
Jeff
Its ok tho...i still think you are a good guy even for a C.O.B
73
Jeff