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Famous_Bit_5119 t1_ja3cndo wrote

What range does it output/ receive?

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FlexingCapacitor t1_ja4akig wrote

That's a great question. I don't have an answer, but it reminds me of when I had a CB installed in my little truck like 30 years ago. I thought the way to go was to get a super long whip mounted on the back bumper cuz I thought the popular roof mounted ones were half-measures. That's when the installer dude informed me that the whip is just the visible part. It has to make contact with the vehicle frame, thereby making the entire vehicle AND the whip the operative antenna. I was like 🤯.

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dzlux t1_ja4lp0w wrote

Bigger antenna helps the most on improving the signal, where larger signal to noise ratio (snr) is the goal. The only real question for your antenna is in choosing which fraction of a wave (1/4, 18, etc) you can live with for antenna length to get the best performance without vehicle operation problems.

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rarebit13 t1_ja6oilr wrote

As I understand it:

Short antenna is shorter range but works best in hilly terrain (signal is 'rounder ')

Long antenna is long range but works better over flat terrain (signal is horizontally 'oblong').

I realise this is actually a function of the dbi but I believe length is inversely related to dbi.

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HighOnGoofballs t1_ja79mjq wrote

Fwiw On boats it’s about how high it is, so it can get past the horizon

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Kevinsound27 t1_ja4meup wrote

I also used to think the ground strap was something loose on the bottom of trucks till my dad explained it’s to ground the radio.

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CypherFTW t1_ja5l3ei wrote

CB radios don't ground to the earth to work, only to the chassis of the vehicle. Those straps were "Anti Static Straps" designed to dispel the static build up from your car. I don't think they were ever proven to work and people pretty much stopped buying them by the end of the 90s. I think one of their claims may have been "improved radio quality" but they had a lot of weird claimed benefits that were largely marketing.

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Kevinsound27 t1_ja5sttu wrote

That makes sense actually. it’s one of those things from long ago I remember seeing but haven’t seen one in a long time.

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dzlux t1_ja4kszz wrote

Radio label says 4 watt transmit, so with a reasonable antenna and terrain, 10-15 miles would be normal.

Antennas are generally full wave, or a precise fraction of a wave for the frequency. With CB radio full wave requiring a ~40 antenna, a 1/4 wave (10ft) or 1/8 wave (5ft) antenna will be most practical with high performance.

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Ok-Hovercraft8193 t1_ja4uaka wrote

ב''ה,

The regulations haven't changed much, although I guess SSB (as can somewhat improve range per watt at the expense of compatibility) is allowed slightly more output power legally.

So, in working order, this is probably about as good as any CB set ever, and for contacting the widest range of them.

It's fun, as is proper ham stuff. Since trucking exists and some emergency services might still even monitor channel 9 somewhere (maybe there was a rare amount of local variation with that?), could still be useful if needed.

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Zugzub t1_ja549cv wrote

There's no way that thing has a 10 mile range.

With a good external antenna it might on a good day hit 5 miles.

With the supplied antenna more like 2 miles.

Antenna quality and proper tuning of the antenna is everything when it comes to range.

As far as wattage goes that's 4 ways pep. Cb radios are AM, amplitude modulation. When you speak into the mic and observe power out put it will vary as you speak. Initially it will swing to 4 watts. But then the modulation limiter will kick in and you will see around 2 maybe 3 watts.

You can remove the modulation limiter. Usually by clipping a diode or removing a transistor. At that point depending on the final output power rating of the final transistor you might see 6 to 8 watts.

A Cobra 149 or Uniden President grant radio could hit 29 to 25 watts once modified.

And a full wavelength in the 11 meter band is 32.125 feet not 40.

As for antennas, you can get a half wave antenna that's only 3 foot long, that's accomplished by winding 16 feet of wire around a fiberglass rod.

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dzlux t1_ja5bhia wrote

You are welcome to have opinions, but arguing about range shortcomings without very specific parameters is pointless. I am traveling down the Texas coastal region today and regularly have 5-10 mile unobstructed line of sight - even a modest monopole antenna will outperform your claims in this area.

> And a full wavelength in the 11 meter band is 32.125 feet not 40.

If you want to be more exact about full wave length in an effort correct someone, then you moght consider explaining how you arrived at “32.125 ft”

CB is 26.965 Mhz - 27.405 Mhz. Which ranges from 36.465 ft to 35.879 ft for a full wave.

Your 32.125 ft would be appropriate for ~30.6m Mhz.

Not that the correcting for exact length adds anything to my comment above, or the one above it……. but whatever. Enjoy yourself.

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[deleted] t1_ja5qkdy wrote

[deleted]

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dzlux t1_ja5ttbk wrote

> …seems we are both wrong.

If it makes you feel better to view an approximate number as wrong, then enjoy it. This is the internet after all.

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takeoff_power_set t1_ja6e6f9 wrote

I've personally had better results than that transmitting on a handheld set to 5w. There are a lot of variables to range on low power, small antenna units like this. Frequency, obstacles, characteristics of the terrain, condition of the antenna and connector, height above ground, background interference etc.

The best thing you can do to help yourself if you need to use one of these in the wilderness is to get as high as safely possible above potential receivers with it before transmitting. I.e. climb a hill or mountain with it if you want to be heard.

A neat trick if you have two decent handhelds and some rope: set one radio up to retransmit what it receives, tie a rope to its lanyard and throw it up into a tree branch as high as you can. With the other unit you can now transmit with your impromptu repeater being (hopefully) significantly higher up and giving you waaay better range. A decade or so ago I set up a very crude pair of solar powered repeaters like this in the mountains, it worked well and I was able to talk to people dozens of miles away on the other side of the mountains so long as I had LOS with the first repeater. The repeaters in trees at mountain peaks had massive transmit range even at low wattage. Not bad for some cheap Quansheng radios

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mkosmo t1_ja7eyk5 wrote

> Antennas are generally full wave

Full wave whips don't work, though... so you wouldn't see one here. You'd have to go dipole or loop, neither of which makes sense in a mobile application.

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dzlux t1_ja999k0 wrote

“Antennas are generally full wave, or a precise fraction of a wave for the frequency.”

Wild. That sentence describes the concept behind any antenna length… and somehow you tried to correct it by picking one length and describing why it won’t work for a specific design?

This is a really negative approach to introduce concepts of antenna design limitations to the conversation.

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mkosmo t1_ja99opx wrote

We’re talking CB, where whips are almost exclusively used. It’s important to note context. When it comes to whips, 5/8λ works, but 1 λ does not.

If we were talking a service where dipoles were relevant, I wouldn’t have mentioned it.

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ericek111 t1_ja6xmp1 wrote

With the proper conditions and antenna? 8000 km.

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