Retevis 900MHz

[PACNWComms]

14 minutes ago, Ian said:

Not even to someone who collects failed techology like that?  :3

They are not even worth the shipping costs, and then I would have to dig for them, somewhere in the garage buried in a box somewhere. eXRS radios were that bad.

[Ian]

Ouch.  Seriously, though, I collect "unicorns" -- things the FCC approved though they violate FCC rules.  FRS radios with detachable antennas, MURS multiservice radios, type-certified DMR FRS radios, weird shit.

[gman1971]

Unicorns... LMAO

[wb2dyb]

I have three of the RT10's. They do work. RX sensitivity pretty good. TX power is lower than my 6580's but it seems adequate for what I needed them for, use within repeater useful range. TX audio is ok, RX has some strange audio expander, like with M's "hear clear". Does not do "squelch tail elimination" when talking into one of my 927 Quantar repeaters. 

It is also DMR and does that very well. 

So for a sub-$100 radio its ok. I'd still make my primary portable a XPR6580 though. Mobiles I use 35 Watt MCS2000's and for repeaters, Motorola Quantar.

GeorgeC W2DB/WQYN409

Crowley, TX

 

[gman1971]

6580 can be had for <100 bucks easily too.

JMO.

[PACNWComms]

8 hours ago, gman1971 said:

6580 can be had for <100 bucks easily too.

Yes, just bought a lot of these for some sites in Middle America, great radios and also use the chargers/accessories for the XPR6550 UHF radios they already had. They were going to spend about $1000-1200 for XPR7580e handhelds, new, and waiting at least six months to receive due to the current supply chain issues. The XPR6580's were ready to ship as refurbished units (re-cased with 80% or more on the batteries guaranteed). 

[gman1971]

Nice... I believe the XPR65x0 radio is a great radio if you can live without a color screen and the arguably ugly looks... it has a mini-coax on the antenna connector like the APX radios... and SMA for the antenna. Receiver is not as good as the XPR Gen2.5 but the 6550 has equal performance in terms of RF receiver to most brand new non Motorola gear...

G.

[WRQX963]

On 2/10/2021 at 3:30 PM, scorpion1200 said:

RT10 900MHz radio only is used for three countries, America, Mexico, and Canada

Where is that first one?
Doesn't America mean two continents?
Mexico and Canada are both in North America.

[SteveShannon]

1 hour ago, WRQX963 said:

Where is that first one?
Doesn't America mean two continents?
Mexico and Canada are both in North America.

America is also commonly used to mean the United States of America. From Wikipedia:

The United States of America (U.S.A. or USA), commonly known as the United States(U.S. or US) or America, is a country primarily located in North America.

[WRQX963]

1 hour ago, Sshannon said:

...a country primarily located in North America.

Is Argentina also in America?
I know they are in South America.

[BoxCar]

13 minutes ago, WRQX963 said:

Is Argentina also in America?
I know they are in South America.

No. America refers to a single country while the word when combined with North or South refers to a continent.

[SteveShannon]

8 minutes ago, WRQX963 said:

Is Argentina also in America?
I know they are in South America.

No. 

Argentina is in South America (a continent).

Argentina is in the Americas (a land mass consisting of two connected continents: North and South America and their surrounding islands. 
Argentina is not in “America” as the term is commonly accepted. 
When you hear other countries refer to the USA they frequently interchange “the United States” or “America”, specifically meaning the United States of America. 

[WRQX963]

4 hours ago, Sshannon said:

 

I get it, Argentina is in an America and America is in an America but they are in different Americas...I guess.

[Ian]

On 2/1/2022 at 9:16 AM, PACNWComms said:

They are not even worth the shipping costs, and then I would have to dig for them, somewhere in the garage buried in a box somewhere. eXRS radios were that bad.

I bought four of 'em on eBay for the collection.  They feel like cheap plastic crap, but they actually work really well over here.  If you ever trip on 'em, I'll absolutely pay to have them shipped.

[KAF6045]

14 hours ago, Ian said:

I bought four of 'em on eBay for the collection.  They feel like cheap plastic crap, but they actually work really well over here.  If you ever trip on 'em, I'll absolutely pay to have them shipped.

You can't have mine -- even if they are museum exhibits

Think I've stopped hitting Batteries Plus to get new rechargeables for them, since they just die from lack of use. (I think I have one set still in the original box -- they were cheap enough to have two sets of the larger model (6-digit "address/hop scheme"), and gave my brother/father sets of the smaller (3-digit) models). At the time they were a interesting variation on "bubble-pack" radios. Pretty sure they used their own hopping system with no attempt at compatibility with commercial systems.

Last purchased Jan 2011 from Fry's Electronics: eXRS 300 pair @ $80, eXRS 100 pair @ $60. A pair of 300s @ $90 in Mar 2010. A pair of 100s @ $75 in April 2010 (alongside Midland 1050s at $75!)

 

 

[tep182]

On 6/1/2022 at 12:21 AM, WRQX963 said:

I get it, Argentina is in an America and America is in an America but they are in different Americas...I guess.

 

Nope.  America is exceptional.   If you had a friend named "Mike" that was wealthy and powerful, everyone would know who you meant when you said "Mike"... even if there were other, failed versions of "Mike".

[tgies]

Sorry to bump an old thread, but for everyone's amusement and edification, here is Retevis admitting to me that the RT10 -- still being advertised as license-free -- actually falls under amateur radio rules.

(Censored some personal information. Also, not sure if I actually got the details of what does/does not make something ISM-legal right on my end -- would be happy to be corrected with the specifics -- but I think I have the gist of it right.)

(

[axorlov]

Does the ISM operation in United States truly requires frequency hopping or similar spread spectrum modulation? Where is it stated? 15.247 describes conditions for the frequency hopping devices, but where it is written that analog FM on fixed frequency (say, with 12kHz channel width) is not allowed?

Edit:
I guess I found it: 15.247.a.2. Minimum bandwidth is 500kHz. Still can be used for DMR, etc. Does anybody have FCC ID for the RT10? Let's see the emission designation.

Edit 2:
Still can't find that analog FM (or AM) is explicitly prohibited. Also can't see where it is explicitly stated that only FHSS modes are allowed.

[KAF6045]

10 hours ago, axorlov said:

Does the ISM operation in United States truly requires frequency hopping or similar spread spectrum modulation? Where is it stated? 15.247 describes conditions for the frequency hopping devices, but where it is written that analog FM on fixed frequency (say, with 12kHz channel width) is not allowed?

First part of 15.247: Note that the purpose of frequency hopping is to minimize interference to other users; using a single frequency with a wider bandwidth may interfere with multiple ISM systems.

Quote

§ 15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

(a) Operation under the provisions of this Section is limited to frequency hopping and digitally modulated intentional radiators that comply with the following provisions:

<SNIP>

(h) The incorporation of intelligence within a frequency hopping spread spectrum system that permits the system to recognize other users within the spectrum band so that it individually and independently chooses and adapts its hopsets to avoid hopping on occupied channels is permitted. The coordination of frequency hopping systems in any other manner for the express purpose of avoiding the simultaneous occupancy of individual hopping frequencies by multiple transmitters is not permitted.

Note to paragraph (h):

Spread spectrum systems are sharing these bands on a noninterference basis with systems supporting critical Government requirements that have been allocated the usage of these bands, secondary only to ISM equipment operated under the provisions of part 18 of this chapter. Many of these Government systems are airborne radiolocation systems that emit a high EIRP which can cause interference to other users. Also, investigations of the effect of spread spectrum interference to U. S. Government operations in the 902-928 MHz band may require a future decrease in the power limits allowed for spread spectrum operation.

[Lscott]

11 hours ago, axorlov said:

Does the ISM operation in United States truly requires frequency hopping or similar spread spectrum modulation?

Not that I’m aware of at least for Amateur Radio. There are a few FM repeaters around on the band. One of the very few Motorola radios I have besides the XPR-6550’s is an XPR-6580. It’s the only radio I have for 33cm so far. And added bonus is it will do DMR too.

The code plug was hacked, using in memory radio CPS changes, to get the radio on the 33cm band. The radio didn’t require any hardware modifications like the Kenwood radios I researched at the beginning.

XPR-6550_6580 Brochure.pdf

[axorlov]

5 hours ago, KAF6045 said:

Operation under the provisions of this Section is limited to frequency hopping and digitally modulated intentional radiators

I saw this. I interpret is as: if your radiator is frequency hopping or digitally modulated, then this section applies. Not correct, you think? There are other sections about 902-928MHz too.

[axorlov]

4 hours ago, Lscott said:

XPR-6580

Great to know!

[Radioguy7268]

Man, we argue about the benefits of 25kHz "wideband" vs. 12.5 with GMRS.  I can't imagine stepping up to a minimum bandwidth of 500kHz!  Imagine the fidelity...  then again, you're still power limited, and you would need to accept any interference.

I think for practical purposes, even if the rules don't spell out a particular protocol that you MUST use for the ISM band, reality is that you're going to need to use spread spectrum to have success.

[WRQX963]

I read over 15.247 and get the idea that the British 100 mw 13cm radios might be legal here for ISM use if they can be made to not go below the bottom of our band.

[Lscott]

2 hours ago, axorlov said:

Great to know!

The attached file outlines one way to do it.

MOTOTRBO too 927MHz Code Plug Mod.pdf