The definitive CCR thread... why you won't really save anything.

[gman1971]

I'll start the Cheap China Radio (CCR) thread by showing this picture.

 

 

That shows the sensitivity of the receiver combined with the channel rejection filtering in dB, which means, any signal value that is above the dBm curve plot will desense the receiver. You can pretty much extrapolate this curve from the last point where it is computed if no advanced filtering is used, like the SLR8000 repeater, with over 120 dB blocking for off frequency stuff, etc.. but unless you have one of those, most mobile radios don't have that kind of additional filtering. So if you live in an are with a noise floor of -50 dBm like I do, pretty much most CCRs will fall apart and desense so bad you won't hear squat. OTOH, radios like the XPR7550e, with super tight front ends, will effortlessly reach over miles when the CCR is deaf as a rock. This also shows why more sensitivity is not better, in fact, more sensitivity with a poor front end filtering means it will desense even faster.

 

IMO, the graph above should be pretty much definitive as to why the pricing is directly proportional to the selectivity + sensitivity on those devices: with the Motorola SLR800 repeater leading the pack at well over 2 grand, the Vertex EVX-5300, new, was around 600 bucks, the TM-V71a, is around 350 bucks new, and well, the GD77 CCR can be purchased new for 65 dollars on eBay. 

 

And here is a very simple procedure to gauge a CCRs performance and if its even worth the expenditure. 

 

1) First off, If no channel selectivity figures are offered, then move on. "These are not the droids you're looking for."

2) Now get the receiver sensitivity figure, usually measured in uV, but with this nice chart you can convert it to dBm at 50 Ohm, link here: http://www.repeater-builder.com/tech-info/measuring-sensitivity/dbm2uv.pdf

3) Knowing that any signal above the receiver sensitivity threshold (at any frequency) will desense the receiver you add the selectivity in dB at 25 kHz to the receiver sensitivity in dBm, pay attention to signage, the sensitivity is negative dBm. 

4) Repeat the same for 12.5 kHz. Now, some brands show even narrower kHz dB figures offered. You can add it and find out, but that is usually not as important as the real selectivity for further away signals.

5) As a general rule, any signal received within the receiver frequency range (and in the CCRs even further than that) that is stronger than the 25 kHz selectivity value calculated will desense the receiver.

 

Have at it, and please, correct me if I made any mistakes.

 

G.

[Lscott]

I'll start the Cheap China Radio (CCR) thread by showing this picture.

 

 

That shows the sensitivity of the receiver combined with the channel rejection filtering in dB, which means, any signal value that is above the dBm curve plot will desense the receiver. You can pretty much extrapolate this curve from the last point where it is computed if no advanced filtering is used, like the SLR8000 repeater, with over 120 dB blocking for off frequency stuff, etc.. but unless you have one of those, most mobile radios don't have that kind of additional filtering. So if you live in an are with a noise floor of -50 dBm like I do, pretty much most CCRs will fall apart and desense so bad you won't hear squat. OTOH, radios like the XPR7550e, with super tight front ends, will effortlessly reach over miles when the CCR is deaf as a rock. This also shows why more sensitivity is not better, in fact, more sensitivity with a poor front end filtering means it will desense even faster.

 

IMO, the graph above should be pretty much definitive as to why the pricing is directly proportional to the selectivity + sensitivity on those devices: with the Motorola SLR800 repeater leading the pack at well over 2 grand, the Vertex EVX-5300, new, was around 600 bucks, the TM-V71a, is around 350 bucks new, and well, the GD77 CCR can be purchased new for 65 dollars on eBay. 

 

And here is a very simple procedure to gauge a CCRs performance and if its even worth the expenditure. 

 

1) First off, If no channel selectivity figures are offered, then move on. "These are not the droids you're looking for."

2) Now get the receiver sensitivity figure, usually measured in uV, but with this nice chart you can convert it to dBm at 50 Ohm, link here: http://www.repeater-builder.com/tech-info/measuring-sensitivity/dbm2uv.pdf

3) Knowing that any signal above the receiver sensitivity threshold (at any frequency) will desense the receiver you add the selectivity in dB at 25 kHz to the receiver sensitivity in dBm, pay attention to signage, the sensitivity is negative dBm. 

4) Repeat the same for 12.5 kHz. Now, some brands show even narrower kHz dB figures offered. You can add it and find out, but that is usually not as important as the real selectivity for further away signals.

5) As a general rule, any signal received within the receiver frequency range (and in the CCRs even further than that) that is stronger than the 25 kHz selectivity value calculated will desense the receiver.

 

Have at it, and please, correct me if I made any mistakes.

 

G.

What is the source you got the graphs from and how were the tests done?

[WRAF213]

Yes, I'd like to see how the tests were done. At best, it's demonstrating adjacent channel selectivity and receiver sensitivity. It's also generalizing all CCRs into the GD-77, which is quite reckless. So, we're trying to point out that these radios are junk, yet trusting the totally-not-copied-and-pasted selectivity measurements the manufacturer provided? Is repeater selectivity measured with cavity filters installed? If your noise floor is -50dBm you should be getting cooked alive.

 

One odd point to mention is that a dBu to dBm conversion isn't as straightforward as it sounds since a lot of handheld radios (especially CCRs) don't present exactly 50 ohms at the antenna.

 

I played around with a service monitor and found that my Connect Systems CS-580 had a receiver that was hotter than any of my commercial radios, and it also has a proper 12.5 kHz channel bandwidth for the narrowband setting (which doesn't really matter since I bet you're using it in wideband anyways).

 

For a well designed receiver, selectivity is a compromise with sensitivity. You can add preselectors and tracking filters, but all of those add insertion loss, which contributes to noise figure. Most CCRs run nearly naked, so the frontend-on-a-chip is exposed behind only a LNA and probably some highpass filters. They can get very sensitive, but this leaves them prone to desense from signals not necessarily near the receiver's frequency. Either way, desense is more complicated than this graph can show.

[gman1971]

WRAF, yes the GD77 is probably one of the worst CCRs out there. While Anytone 878 radios fare much better, these still desense easier than the EVX radios I have.

 

LScott, The chart was calculated using the specifications printed on the radio service manuals.

 

For the GD77, the selectivity figures were calculated using a VNA using a similar procedure to the one outlined here.

The sensitivity of the GD77 is claimed by the manufacturer to be -122.dBm

 

The point of this chart was to show at a quick glance why these radios are inferior to things like the SLR8000 repeater from Motorola... I understand desense is a fairly more complex issue, but the chart is easy to read for most people. If you can determine the noise level in you area, that is half of the battle right there.

 

G.

[WRAF213]

The SLR8000 is a terrible benchmark to use since NOBODY is using that as their primary GMRS radio, particularly as a mobile or portable (nor is it Part 95 type accepted). Repeaters are expected to have excellent desense rejection since they're usually running a 25-40 watt transmitter on the same antenna as the receiver. A lot of the nicer handheld radios have tracking filters on the frontend that gives them stronger desense protection, and you won't find that feature at the CCR price point. You get what you pay for; don't forget the cost of a new commercial radio.

[gman1971]

WRAF, I don't think I ever stated, nor implied, that anyone was/should be using the SLR8000 for GMRS. I just pointed the figures to show it on a chart. Whether it is or not part 95 accepted it is hard to argue that the figures on that thing are just amazing, plus it has additional blocking of 110 or 120 dB, so its probably loaded up with filters of all kinds... hence why that is the kind of receiver front end performance one should strive to get, compared to the bottom of the barrel GD77... which is fine for certain things.

 

Yes, thats it right there WRAF: "A lot of the nicer handheld radios have tracking filters on the frontend that gives them stronger desense protection, and you won't find that feature at the CCR price point."

 

I understand that for very advanced guys/gals, like you, the statements I've made are like 1st grade math, but for some of us who trained in other fields, this is the kind of stuff that marketing preys upon to sell CCRs. It would've saved a lot of hassles, time, and ultimately money, should I've have known about what I posted in here. Is it simplified? Yes, but so are Newton's classical mechanics vs the more complete Maxwell's equations... yet we still use Newton's for pretty much anything were v << c... 

 

In the end its someone else's money, they can spend it however they like it. I only wrote this in an effort to help others, who may, or hopefully not, be as clueless as I was when I started buying radio gear.

 

G.

 

 

The SLR8000 is a terrible benchmark to use since NOBODY is using that as their primary GMRS radio, particularly as a mobile or portable (nor is it Part 95 type accepted). Repeaters are expected to have excellent desense rejection since they're usually running a 25-40 watt transmitter on the same antenna as the receiver. A lot of the nicer handheld radios have tracking filters on the frontend that gives them stronger desense protection, and you won't find that feature at the CCR price point. You get what you pay for; don't forget the cost of a new commercial radio.

[WRAF213]

But it's important to realize when it's not practical to pay for more selectivity. Good commercial handhelds have enough selectivity to allow full-duplex operation by one operator, with a few feet of antenna separation. Good mobiles do better than that. If that's not enough desense protection, there's other issues at play. There's no improvement to be made if there isn't an issue, so it's just wasted money and/or lost functionality.

 

CCRs work just fine as transceivers for 99% of the population. Yes, they don't work in the busy RF environments found at an enthusiast's base station, a command post, or when working near other operators on different in-band channels. They're cheap, show people what the hobby can offer, and include a lot of features (like FPP and ridiculous channel capacity) that new operators need to find their niche within the hobby and understand what parameters need to be configured to operate cleanly on someone else's system. And when they break (probably due to a novice operator blowing out the finals or dropping it), it's not a big investment being lost. They exist in the market for a reason: because they do work, unlike what the topic's title implies. They wouldn't sell if they didn't. It's important to understand their limitations, but they're not as severe as you're making it out to be.

[gman1971]

Well, sure, these radios worked much better at our previous house, but since moving to this new house (near the giant antenna) these things aren't cutting it anymore and I never really knew why...  That is why I felt cheated from those radios, once I started to get serious I realized I really threw my money away, as some of those radios I got for 40 dollars are now 9 and no option to ditch them... and then considering the fact that some of the commercial gear available is so cheap, it almost makes no sense to take the bait of the flashy screens, and bells and whistles when these lack in the most important aspect, the RF performance. 

 

I own a ton of CCRs myself, from cheap BF-888S for house intercom to DJ-MD5, GD77s, etc; yes, they work, and these are what got me back into radios... just don't expect much from those once you really want to reach far. 

 

G.

 

 

But it's important to realize when it's not practical to pay for more selectivity. Good commercial handhelds have enough selectivity to allow full-duplex operation by one operator, with a few feet of antenna separation. Good mobiles do better than that. If that's not enough desense protection, there's other issues at play. There's no improvement to be made if there isn't an issue, so it's just wasted money and/or lost functionality.

 

CCRs work just fine as transceivers for 99% of the population. Yes, they don't work in the busy RF environments found at an enthusiast's base station, a command post, or when working near other operators on different in-band channels. They're cheap, show people what the hobby can offer, and include a lot of features (like FPP and ridiculous channel capacity) that new operators need to find their niche within the hobby and understand what parameters need to be configured to operate cleanly on someone else's system. And when they break (probably due to a novice operator blowing out the finals or dropping it), it's not a big investment being lost. They exist in the market for a reason: because they do work, unlike what the topic's title implies. They wouldn't sell if they didn't. It's important to understand their limitations, but they're not as severe as you're making it out to be.

[RCM]

Well, sure, these radios worked much better at our previous house, but since moving to this new house (near the giant antenna) these things aren't cutting it anymore and I never really knew why...  That is why I felt cheated from those radios, once I started to get serious I realized I really threw my money away, as some of those radios I got for 40 dollars are now 9 and no option to ditch them... and then considering the fact that some of the commercial gear available is so cheap, it almost makes no sense to take the bait of the flashy screens, and bells and whistles when these lack in the most important aspect, the RF performance. 

 

I own a ton of CCRs myself, from cheap BF-888S for house intercom to DJ-MD5, GD77s, etc; yes, they work, and these are what got me back into radios... just don't expect much from those once you really want to reach far. 

 

G.

You need to take on ECRs next: Expensive Chinese Radios. Still made in China, but repackaged with an American name and a price tag to rival that of a new Icom.

I think everybody here knows what radio I'm talking about.

[gman1971]

My EVX-5300 radios are made in China and branded as Vertex Standard, I know these don't desense as bad as the CCRs do... so its just the C. part of the acronym what I think there should be some awareness. The Vertex Standard radios made in Japan seem, in paper at least, a lot better than the ones made in China.

 

I haven't tinkered with Hytera radios and probably never will...  

 

Motorola radios AFAIK are made in Malaysia, not really China, but yeah... I understand the point.

 

G.

[RCM]

My EVX-5300 radios are made in China and branded as Vertex Standard, I know these don't desense as bad as the CCRs do... so its just the C. part of the acronym what I think there should be some awareness. The Vertex Standard radios made in Japan seem, in paper at least, a lot better than the ones made in China.

 

I haven't tinkered with Hytera radios and probably never will...  

 

Motorola radios AFAIK are made in Malaysia, not really China, but yeah... I understand the point.

 

G.

Nope, I don't think you do. I was talking about Midland.

[gman1971]

I had no idea Midland was made in China... so if that is the case then perhaps it falls in the EVX category? Designed in another country and built in China? Or are Midland radios just rebadged TYT stuff? 

 

G.

 

Nope, I don't think you do. I was talking about Midland.

[RCM]

I had no idea Midland was made in China... so if that is the case then perhaps it falls in the EVX category? Designed in another country and built in China? Or are Midland radios just rebadged TYT stuff? 

 

G.

They're just reflashed and rebadged Chinese stuff. A member who hasn't been around for awhile, Hans, posted exactly what they are awhile back.

[gman1971]

That is most unfortunate to hear, so therefore these should also be added in the CCR category and avoided as well. I think Motorola (Vertex Standard), Icom and Kenwood are probably the only few brands I would consider at this point. In the end, buying a nice EVX-539 with dotmatrix display UHF G7 model will save you a lot of trouble in the long run, plus those radios are pretty well built and will survive pretty much anything you throw at them.

 

But that is just me.

 

G.

 

They're just reflashed and rebadged Chinese stuff. A member who hasn't been around for awhile, Hans, posted exactly what they are awhile back.

[Downs]

They're just reflashed and rebadged Chinese stuff. A member who hasn't been around for awhile, Hans, posted exactly what they are awhile back.

This is certainly the case on their dual band HAM radio. Their DBR2500 is a rebadged AT778 from Anytone.

 

Rugged Radios is infamous for this rebading. Selling UV5Rs with their tag on it for 80 dollars. Their 60 watt vhf radio they sell for 400 dollars is a rebadged 130 dollar TYT TH9000D.

 

Sent from my SM-G892A using Tapatalk

[gman1971]

Anytone, some of their latest stuff is certainly better, but TYT (and their clones), in my experience, they are the worst of the CCRs, even crappier than the UV5R, their front ends lacks of any filtering and just desenses.

 

G.

[RCM]

This is certainly the case on their dual band HAM radio. Their DBR2500 is a rebadged AT778 from Anytone.

 

Rugged Radios is infamous for this rebading. Selling UV5Rs with their tag on it for 80 dollars. Their 60 watt vhf radio they sell for 400 dollars is a rebadged 130 dollar TYT TH9000D.

 

Sent from my SM-G892A using Tapatalk

Rugged Radios also misleads people to believe that as their customer, they can legally transmit on business band itinerant frequencies under RR's license. It's not a 100 percent lie*, but it is a gross misrepresentation.

 

* A customer can do that at certain events where Rugged Radios is physically present and gives the customer express permission to transmit on the specific frequencies in use, but only at the event location and while the event is going on.

[Downs]

They have a ton of business band frequencies that arent even theirs on there. And unless you corner them they try to skirt answering any questions about licensing.

 

Theyre a shady underhanded company but they have a good marketing team and sponsor the crap out of the off road and racing community.

 

Sent from my SM-G892A using Tapatalk

[gman1971]

That is a new level of misrepresentation.... who knew...

 

Rugged Radios also misleads people to believe that as their customer, they can legally transmit on business band itinerant frequencies under RR's license. It's not a 100 percent lie*, but it is a gross misrepresentation.

 

* A customer can do that at certain events where Rugged Radios is physically present and gives the customer express permission to transmit on the specific frequencies in use, but only at the event location and while the event is going on.

[Ian]

But it's important to realize when it's not practical to pay for more selectivity. Good commercial handhelds have enough selectivity to allow full-duplex operation by one operator, with a few feet of antenna separation. Good mobiles do better than that. If that's not enough desense protection, there's other issues at play. There's no improvement to be made if there isn't an issue, so it's just wasted money and/or lost functionality.

 

CCRs work just fine as transceivers for 99% of the population. Yes, they don't work in the busy RF environments found at an enthusiast's base station, a command post, or when working near other operators on different in-band channels. They're cheap, show people what the hobby can offer, and include a lot of features (like FPP and ridiculous channel capacity) that new operators need to find their niche within the hobby and understand what parameters need to be configured to operate cleanly on someone else's system. And when they break (probably due to a novice operator blowing out the finals or dropping it), it's not a big investment being lost. They exist in the market for a reason: because they do work, unlike what the topic's title implies. They wouldn't sell if they didn't. It's important to understand their limitations, but they're not as severe as you're making it out to be.

 

Believe it or not, the GD-77S is my favorite radio at the moment.  It solves practical problems by slinging squiggles, and it's even type-accepted as a business radio (No FPP).  As such, it qualifies as the "surplus commercial equipment" that the 2017 memorandum stated was never intended to be banished from the GMRS, and I believe it's legal under the latest regulations.

 

And at five watts, it's my most powerful cheap squiggle-slinger.  Used with Motorola gear (2W) on both high and low (1W), it's absolutely comprehensible in two directions when cell phones aren't getting enough signal to send a text message.

 

Is it "good"?  Apparently not.  Is it good enough?  For me and those like me, yeah it is.  (And if it gets dropped, I didn't just break irreplaceable hardware!)

 

Edited to add:  And at 5w back and forth, it'll reach from handie to handie all the way to our grocery store, and inside too.  As far as I'm concerned, that performance is mind-blowing.

[gman1971]

I am glad you're happy with the GD77s, but if you really want to see mind-blowing performance then you should get yourself a pair of XPR7550e and see...

 

Also, if you are using the GD77s on DMR then it is not legal. GMRS is FM ONLY. Also, to be 100% compliant then you should be using 20 kHz wideband, and because I know that the GD77s won't do 20 kHz, then you should be using 12.5 kHz instead. If you're using 25 kHz then it is not legal either.

 

You speak like people here in the forum don't know what they are talking about, they are called CCR for a reason. Don't mislead people, dude, grocery store could be 1/2 miles away from home. That is hardly mind-blowing. One radio sitting on a 10 floor building to ground level, not really mind blowing either. I've reached 30 miles using a 2W VHF MURS Ritron portable... does that mean the performance was mind-blowing? Certainly not, why? b/c the receiving radio (a TYT8000E with crossband repeat) was strapped to a drone flying some hundred feet up in the air in the middle of nowhere.

 

Also, for the GD77S, at 75 dollars a pop you are being ripped off, man. If you want cheap, try the Baofeng DM-V1, which is basically a GD77s, except its 25-29 dollars a pop. The DM-V1 will also do DMR if you really want to have DMR (not legal in GMRS). Then there is the Baofeng BF-1801, 45 dollars a pop and its a GD77 clone, with a REAL screen. However, at the price you paid for those overpriced CCRs you could've bought a TYT MD380 UHF (single band, not the dual band), with a color screen and, IIRC a real superheterodyne receiver too... and have a better than mind-blowing performance over the GD77S... I think paying 77 bucks for a CCR without a screen is a ripoff, fortunately tho, it is great to know that, at least, the performance is mind-blowing. You could've achieved the same kind of mind-blowing performance with a pair of BF-888S, except for 18 dollars, and have enough cash left to purchase a used Vertex Standard EVX-531 on eBay, maybe 2 if you look hard enough.(since you seem to like no-screen DMR capable radios)

 

Also, I didn't make this post b/c I am brand name snob that just wants to bash on CCRs for the heck of it, so, without further delay let me introduce you to my extensive CCR collection, and the reason why I made this post.

 

-15 BF-888S, yep, at 9 dollars a piece, they work great for my house intercom, and if anybody destroys one, guests kids, anybody, be it by throwing it the toilet, smashing it with a hammer, etc, etc, won't be crying over it. Receiver on those is BETTER than the GD77s.

-10 Baofeng BF-1801, basically a GD77 clone. Those work great as intercoms on both DMR and FM with the signaling stuff.

-5 Baofeng DM-V1 (which is basically a GD77s, but UHF only, can be modded to do VHF, but haven't tried to do that) Great for store floor intercom, and at 25-29 bucks a pop, its hard to argue with that.

-2 GD77, I got ripped off twice before I found out that the Baofeng BF-1801 was the same radio, at HALF the price. The GD77 is a ripoff, get the BF-1801 instead.

-4 Alinco DJ-MD5 DMR/GPS. Not exactly a CCR at 189 a piece, but these are usually our carry around radios, one for each member of the family (old enough to use a radio) Good balance between features and RF performance, for the price, of course.

-5 Baofeng GT-3, (3 dead now) those were the radios that got me into FRS then into GMRS.

-4 TYT 8000E.

-1 Anytone INSTG8R

 

Forgot to state what I no longer own but that was also extensively tested.

-1 Retevis RT52, one of the worst, if not the worst radio front end I've ever benched, returned.

-3 Anytone 878UV. Too big, I liked the Alinco MD5 beter, returned them all.

-2 UV-5R. All dead.

-2 UV-82. Gave them to friends.

-2 UV-3R. All dead.

-Ailunce HD1. Very poor performance, returned.

 

I've tested all these radios in nearly every possible scenario you can think of, with several types of ducks, high gain antena, etc, and with the exception of the Alinco DJ-MD5/Anytone 878 (which seems to have better front-end filtering that all those CCRs) none of these radios can compete in terms of range and overall performance to my commercial grade gear, especially when operated in crowded RF areas, which is pretty much anywhere where computers operate these days. Inside a mall the difference is night and day.

 

 

G.

 

 

Believe it or not, the GD-77S is my favorite radio at the moment.  It solves practical problems by slinging squiggles, and it's even type-accepted as a business radio (No FPP).  As such, it qualifies as the "surplus commercial equipment" that the 2017 memorandum stated was never intended to be banished from the GMRS, and I believe it's legal under the latest regulations.

 

And at five watts, it's my most powerful cheap squiggle-slinger.  Used with Motorola gear (2W) on both high and low (1W), it's absolutely comprehensible in two directions when cell phones aren't getting enough signal to send a text message.

 

Is it "good"?  Apparently not.  Is it good enough?  For me and those like me, yeah it is.  (And if it gets dropped, I didn't just break irreplaceable hardware!)

 

Edited to add:  And at 5w back and forth, it'll reach from handie to handie all the way to our grocery store, and inside too.  As far as I'm concerned, that performance is mind-blowing.

[n4gix]

Also, for the GD77S, at 75 dollars a pop you are being ripped off, man. If you want cheap, try the Baofeng DM-V1, which is basically a GD77s, except its 25-29 dollars a pop. The DM-V1 will also do DMR if you really want to have DMR (not legal in GMRS). Then there is the Baofeng BF-1801, 45 dollars a pop and its a GD77 clone, with a REAL screen.

Since when did they remove the screen from the GD-77? I just looked at mine and the screen is still there...

 

I'll agree that the GD-77 is a complete piece of sub-standard parts, as is the TYT MD-2017 with its stupid trackball. My HD-1 is my second favorite HT at the moment, with the AT-878 currently in the #1 spot.

 

While I do love my XPR-7550 (not e model), I haven't actually carried it in over a year.

 

[gman1971]

He meant the GD77 S, the S model has no screen, and that is an overpriced CCR. The BF-1801 (with screen, a GD77 clone) has its place: its a cheap intercom radio for short range comms.

 

https://www.anyradios.com/wp-content/uploads/2018/06/Radioddity-GD-77S-DMR-Dual-Band-Dual-Time-Slot-Ham-Amateur-Two-Way-Radio-Digital-Analog-4.jpg

 

 

 

I understand, I carry an Alinco MD5, which is basically a small 878, I like having the dual band option, even though I am not a ham, I have pretty much every single ham FM repeater in Wisconsin punched in the radio, in case I ever need help, or in an emergency. Most of these no screen radios are kinda limited for anything beyond store floor intercom (which is what they are designed to do, anyways)

 

There is a noticeable difference in Receiver performance between tne XPR7550 and the XPR7550e. I don't carry one b/c I don't have one, yet. Aside from the price tag, you're boxed in a band, either VHF or UHF... can't do anything to convert... at least I haven't taken one apart to see what makes these radios different... if its a software (firmware) thing, or a physical hardware change.

 

G.

[gman1971]

Also, my primary GMRS long range link is all done using Vertex Standard commercial gear. As I've quickly (and expensively) realized, sticking anything UHF non-commercial grade to the Diamond X50C2 (a 7.2 dBd UHF gain vertical antenna) immediately blanked out, desensed, the receiver due to the massive RFI coming from the 1400-foot Candelabra tower that is less than 2 miles from my house... None of those CCRs has afforded me more than ~2 miles range (except the MD5, which is an improvement, but at 189 a pop, its hardly a CCR), no matter what kind of antenna or how high it was placed, even with a couple of 100 dollar cavities... these CCRs couldn't hear squat, not even the NOAA stations, except for the one at 162.550, which is coming from the 1400-tower 2 miles from home. When you want real range, measured in tens of miles (rather than tenths of an inch), range that works reliably, its time to save up and get a real Motorola/Vertex/Kenwood/Icom radio.

 

Now, if your aspirations are to reach the grocery store down the street, awesome, a CCR might be enough. But when I hear guys like @marcspaz talking about how he was chatting with guys over Spain from the US over HF radio, that IS mind-blowing... grocery store? not so much, man. Maybe it was mind-blowing back when Marconi invented the radio... nowadays? the bottom of the barrel BF-888S can do it too, for 9 dollars a pop.

 

Then there is the Zello app, if you like two-way style comms, it uses the cellular network and its free!, better, and more reliable than any CCR would ever be. 

 

G.

[n4gix]

There is a noticeable difference in Receiver performance between tne XPR7550 and the XPR7550e. I don't carry one b/c I don't have one, yet. Aside from the price tag, you're boxed in a band, either VHF or UHF... can't do anything to convert... at least I haven't taken one apart to see what makes these radios different... if its a software (firmware) thing, or a physical hardware change.

When I first entered the DMR portion of ham radio, I got a good deal on a really well cared for XPR7550 (UHF). I had a custom leather holster made for it, along with the D-Ring for my belt. While it looks nice it is quite heavy, at least compared with my current favorite the AT-878 which weighs just over half as much, is about half the size, and has three times the features as the XPR7550.

 

The first time I carried to Dayton for the Hamvention, I found to my dismay that while I had packed a half-dozen HTs along on the trip (why I have no idea!), I had forgotten the charger for the XPR7550!

 

Fortunately, one of my DMR friends had an Impress charger and hand mic at his booth, so I bought both and all was well again. Now I find myself not even having turned on the XPR7550 for nearly two years. I have the software and programming cable, two chargers, two batteries, the leather holster and speaker mic and need to find a good home for this package. I do keep the batteries rotated and freshly charged though.

 

Now I've found that the battery on my GD-77 has gone bad. It won't hold a charge at all. Thirty seconds fresh off the charger and the radio loses power. I'm not sure about replacing the battery. I may just toss the radio in the trash.

 

I need to sell my MD-2017 and Ailunce HD-1 if possible. I just don't need that many HTs cluttering up the house.

 

It's too bad the AT-578 doesn't have a separation kit, as I'd really like that in my mobile. Running it in 220/440 DMR crossband would be nice. At least then I'd get some use out of my 220 HT that otherwise just sits around feeling lonely. I'm blessed with having a very wide-area 220 repeater here in NW Indiana, but no one else either uses it or has a radio...

[gman1971]

When I first entered the DMR portion of ham radio, I got a good deal on a really well cared for XPR7550 (UHF). I had a custom leather holster made for it, along with the D-Ring for my belt. While it looks nice it is quite heavy, at least compared with my current favorite the AT-878 which weighs just over half as much, is about half the size, and has three times the features as the XPR7550.

 

The first time I carried to Dayton for the Hamvention, I found to my dismay that while I had packed a half-dozen HTs along on the trip (why I have no idea!), I had forgotten the charger for the XPR7550!

 

Fortunately, one of my DMR friends had an Impress charger and hand mic at his booth, so I bought both and all was well again. Now I find myself not even having turned on the XPR7550 for nearly two years. I have the software and programming cable, two chargers, two batteries, the leather holster and speaker mic and need to find a good home for this package. I do keep the batteries rotated and freshly charged though.

 

Now I've found that the battery on my GD-77 has gone bad. It won't hold a charge at all. Thirty seconds fresh off the charger and the radio loses power. I'm not sure about replacing the battery. I may just toss the radio in the trash.

 

I need to sell my MD-2017 and Ailunce HD-1 if possible. I just don't need that many HTs cluttering up the house.

 

It's too bad the AT-578 doesn't have a separation kit, as I'd really like that in my mobile. Running in in 220/440 DMR crossband would be nice. At least then I'd get some use out of my 220 HT that otherwise just sits around feeling lonely. I'm blessed with having a very wide-area 220 repeater here in NW Indiana, but no one else either uses it or has a radio...

 

The 7550 is an expensive radio, and after losing my Alinco MD5 I can't even begin to imagine how devastated I would've been losing an XPR7550 (E or not)  So I can see why someone would keep that baby home unless it was law enforcement, fire, ems... etc.

 

I agree, the 878 has far more features than the XPR7550, but the RX performance of the 7550 is much better, while the 878 is a huge step up from most of the CCRs, (200+ is hardly a CCR anyways, like the MD5). Inside my work place the EVX radio can hear much further than the MD5... I have yet to test the 578, which has a dual conversion hybrid receiver with crystal filters for selectivity.

 

At 390 bucks the AT-578 is hardly a CCR tho, its closer to Hytera in terms of RF performance than any of its portable direct conversion ancestors... (868, 878, MD5, 6x2) which are pretty decent, but no match for double conversion superhets like the Motorolas or the Vertex, Kenwood, Icoms... etc.

 

With that said, when it comes to multiband performance I think the 578 hits the mark on features/performance. Its tri-band out of the box, which is pretty much the only mobile that I am aware of that will do triband, crossband, full duplex, etc... The TYT 9600 mobile is a sorry excuse for a radio, really, expensive, full of bugs, poor RF performance... so the AT-578 seems like the only option if you want to listen to DMR traffic across the entire VHF/UHF bands without carrying two radios.

 

The separation kit is surely missed, but let me tell you, for a radio made overseas I am genuinely impressed. I have it on my desk above my EVX-5400, tuned to the Madison 700...  works great. Even inside my office, which is full of computers, monitors, and all kinds of RFI noise... the thing is full quiet when the repeater talks... even with a 1/4 wave VHF mag mount stuck atop a pizza pan over the highest shelf on the room. The GD77 can't hear anything if you connect it to the same antenna, other radios hear a lot of the RF noise from the computers etc, but this thing is dead quiet, just the person talking... which is basically like the TM-v71a or the TH-F6a or the EVX-5400 underneath...

 

G.