Ok, school me on coms

DaveInDenver

Expedition Leader
#47
3dB = 2x ERP. 6db = 4x ERP. 4xERP is NOT 4x range.
FWIW, as you know but in case anyone wants the rule of thumb, you figure 6dB of gain gives about 2x the distance. If someone wants to do the real calculations the link budget is based on Friis' equation for free space propagation. You can get the 6dB anyway you wish. You usually have most control over transmitter power and antenna gain (either TX or RX) but potentially receive amplifier or sensitivity can be improved. Which is why you'll sometimes see me dig on cheap Chinese radios with poor rejection and sensitivity, they in effect reduce link budget.

If you're paying attention you can estimate range increase by taking the square root of the absolute power increase. IOW, a 6dB gain is 4x power and SQRT(4) = 2. Put another way, going from 5W to 50W is a 10x power increase or 10dB of gain. This gets you in theory 3.16 times the range. To get the next 3.16 times range requires 500 watts or 100dB of gain from your radio or antenna. You can imagine the way this is working by using a light bulb or candle. The 5W omnidirectional (exposed bulb) compared to a 5W in a tightly focused pencil beam.

This is how gain works, it's focusing energy. But the focus of the light is the antenna directionality, so high gain means you change where the energy is radiating. A 1/4 is in this example omnidirectional. An antenna with gain would be like putting a mirror behind your bulb, in effect doubling output in one direction while putting another in the shadows. RF is the same, an antenna with gain will have orientations where it's not radiating energy and won't receive any (this is antenna reciprocity, it receives like it transmits more or less).
 
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#48
I also want to plug a couple of podcasts that are useful for learning more about HAM radio. You can listen to these and therefore learn while driving or working on your truck.

The Ham Radio Workbench podcast originally started by Cale Nelson K4CDN, George Zafiropoulos KJ6VU, and Jeremy Kolonay KF7IJZ, along with other regular guests:

http://www.hamradioworkbench.com

I also listen to the amp-hour podcast. It's mostly non-HAM, but they interview a bunch of SDR folks like Mike Ossmann, Ettus Research, etc. (in the real world, cheapo Baofeng HT's are actually pretty awesome tools used by a LOT of research folks. As opposed to some of the folks on here who aren't RF engineers, yet seem to know everything about anything HAM, which makes them uniquely suited to condemning Baofengs) which is all relevant to HAM.

https://theamphour.com/
 
#54
Well thank you guys for all the great info...again. I didnt expect to get such responses :) I'll be ordering some books here soon as I'm done grading finals, and I'm sure I'll have more questions. Would you guys recommend searching out a local 'club' as well, or just do self study?
 
#55
I also want to plug a couple of podcasts that are useful for learning more about HAM radio. You can listen to these and therefore learn while driving or working on your truck.

The Ham Radio Workbench podcast originally started by Cale Nelson K4CDN, George Zafiropoulos KJ6VU, and Jeremy Kolonay KF7IJZ, along with other regular guests:

http://www.hamradioworkbench.com

I also listen to the amp-hour podcast. It's mostly non-HAM, but they interview a bunch of SDR folks like Mike Ossmann, Ettus Research, etc. (in the real world, cheapo Baofeng HT's are actually pretty awesome tools used by a LOT of research folks. As opposed to some of the folks on here who aren't RF engineers, yet seem to know everything about anything HAM, which makes them uniquely suited to condemning Baofengs) which is all relevant to HAM.

https://theamphour.com/
I don't condemn Baofengs. I have a UV-5r myself and it's a lot of radio for the money. That said, it is pretty complex to program, which is why I don't often recommend them for beginners. OTOH, once programmed, they're pretty easy to use and are great for the trail, particularly when combined with a magmount (or similar) antenna.
 

axlesandantennas

Formerly Double-Desert
#56
As the title suggests. I've done a lot of reading over the last few years, and have now just simply become overwhelmed with so many options and technologies - especially relating to HAM's. There seems to be some contradicting information, so I was hoping for input to sort it out, or at least be pointed in the right direction.

I am a big supporter of multiple facets of coms. I always run the standard CB, and have been wanting to dip into the HAM world also. However, now there is a big push it seems for the additional FRS/GMRS, and now even sending data through HAM freqs?

So, CB and sat options aside, and forum searching aside (which I have done plenty!), I'm curious to hear where are some good sources for solid info and data on:
HAM - yes I realize you need a license, and am hoping to find a local 'club' to work on that with
FRS/GMRS - yes I realize you need a license for some of the freqs
Celle extenders
Other options I'm not aware of (not including InReach)

From my understanding, weboost is one of the better options for cell extenders.

I have recently considered the addition of the Midland MXT400 to add to the coms options. It is my understanding this works on FRS and GMRS freqs?

But as for HAM, here is where I am honestly totally lost. I certainly want to have emergency coms options, but also want to be able to just chat with random people all over the place. I have for a while now considered the Yeasu Ft-875 for its versatility; however, have only recently (in the last few months) seen multiple forums discussing the disadvantage of having an 'all in one' radio, and instead recommending splitting it up to two radios, I think one for HF, and the other for UHF/VHF? Now, to compound this, police/fire/emergency responders - are they also on HAM freqs as I understand it, or do you still need a dedicated 'scanner' to stay up to date on happenings? And what about this whole 'data transfer' and 'texting' and 'internet for computer' stuff I have been reading about lately? Likely much more than what I need, although in specific situations it might be nice to have the option if this in fact is legit.

Lastly - any personal experiences with the President McKinley (CB)?

In any case, the HAM side of things is my biggest confusion point, and due to recent readings, I am now quite confused. Looking forward to getting some direction form the community! Thank you in advance (I may be slow to reply).
I've been using CB and ham radio since the early 90's. Lets see if i can answer a few questions:

I personally like CB. It's inexpensive, easy to use (channels vs frequency), readily available (get an entire setup in Walmart), nearly universal (truckers, jeep/off road clubs, blah blah).

Ham/ Amateur radio is leaps and bounds better than CB but carries quite a bit of baggage. Outside of crappy ChiComm junk like baofeng (or whatever the new flavor they are selling now is) the transmit and receive is much much better. FM (primarily VHF and UHF) sounds like a phone call most of the time. AM bands sound really good. Single Side Band (SSB) is awesome once you figure it out. However, you need a license, which you must take a test (three total for the full monty). Gear can get expensive real quick. But that expense gets you quality gear. Range is down the road to around the globe.

First responders are not really communication guys. Yeah, you might have a few who know what they are doing, but normally they are channelized. They are not going to be digging around on a band looking for a signal. They are going to monitor each other on a certain set of channels, much like MURS, CB, etc. (the channel vs Freq part).

Don't get bogged down in the data transfer computer internet over radio stuff. Concentrate on what you want to do (voice vs Data) and use that as a foundation. There is tons of stuff about ham radio that I only have a passing understanding of and quite frankly don't care about. I want to be able to find a freq and talk on it. Yes, I can do some of the digital stuff, but you need to understand the foundation first. It gets too confusing too quickly when other hams try to get you interested in everything all at once. Often times they are way too pushy. I've seen lots of folks start out super interested in ham radio only to permanently turn off their rigs because other hams try to get them interested in what they want, not what the new guy wants.

That last part brings me to clubs. I have tried over the years to be part of a few clubs and have always left after a few months. My experience is that it becomes way to "my way or the highway". Lots of old farts with too much time on their hands bemoning how great ham radio was before taking away the morse code requirement. I'm sure there are some good ones out there but I have yet to find one.
 
#57
Hey all! I'm back!

As I continue studying, reading and researching I figured it would also be a good idea to research specific radios. I've settled on the 2m/70cm as a starting point - although I'm sure this will turn into a hobby soon.

I'm curious if anyone has experience with the Powerwerx DB-750X.
https://powerwerx.com/db750x-dual-band-commercial-mobile-radio

It doesn't seem to be as 'well known' as others I've looked at, and so far much of the research I've done shows it to be reviewed equally good and bad.

Does anyone have an experience with this particular one? Or any suggestions for something comparable.
 

DaveInDenver

Expedition Leader
#58
Powerwerx has been around a while and AFAIK reputable. I have one of their power supplies that's been fine for a few years and use them for Powerpoles and other stuff sometimes.

This radio appears to be a copy of the Yaesu FT-8800 without the ham band limitations. There are other companies selling similar radios I think, so it's probably coming from the same place as Baofeng and the other brands.

Yeasu discontinued the FT-8800 but they still sell the FT-8900, which included some 6m and 10m coverage. That goes for about $340 at the typical outlets and will be a well known, solid radio. I'd personally buy a new FT-8900 or find a used FT-8800.

https://www.universal-radio.com/catalog/fm_txvrs/0890.html

They say it comes with a Part 90 certification, so maybe it's a fine quality radio. I don't have any experience with it personally, although I do have a Chinese radio (Connect Systems) along with Yeasu, Icom, Vertex and Motorola. Even if it's a good brand and model the build quality on the Chinese stuff leaves something to be desired IMO. They are improved over a few years ago but still not great. You can tell, things like the buttons feel poor and wear out quick, the firmware has glitches, that sort of thing.
 
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#59
Thank you Dave! That's sorta what I was figuring. I appreciate the link to the Yeasu also. I noticed the 8900 is a quad band. From some other research and reading I was under the impression this isn't the greatest way to go, but maybe its just more the matter of preference?
 
#60
Thank you Dave! That's sorta what I was figuring. I appreciate the link to the Yeasu also. I noticed the 8900 is a quad band. From some other research and reading I was under the impression this isn't the greatest way to go, but maybe its just more the matter of preference?
A quad band radio isn't necessarily an issue, but a quad band antenna will be of some compromise.
Also, a Tech licensee couldn't use the 10m part of the 8900 as it is FM and the Tech allocation is only in the SSB portion of the 10m band.
Not sure there is a whole lot of 6m or 10m FM anyways, at least not at the moment. Maybe in 6 years.
 
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