tweiss3
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Posts posted by tweiss3
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16 hours ago, Lscott said:
Well an update on the TK-3200 Protalk. Just got home from work and loaded the hacked code plug in the radio. It seems to work just fine on the local repeater in the area for GMRS so I count this as a success.
Now all I have to do is figure out how to use the full 8 channels, at least the selector switch on top has detentes for 8 with a channel stopper after two. Have to think about that a bit.
What does the radio do when you go to channel 3?
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I'm interested in this project. This seems the same process as getting on 902MHz for ham. I would bet GMRS wouldn't be a problem, firmware probably isn't smart enough to block that out completely. Getting down to 440MHz might prove difficult. I do wonder where the hard stop is at the bottom.
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Did you download the specific driver from bluemax49er?
Also, you may need to change the com port number, usually between 0 and 3, and select the appropriate port number in the CE27.
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look up the FCC ID, it will show what the frequency range for that ID/transmitter is.
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What radio were you using? I haven't made it successfully, but my understanding is that even with Doppler, the frequency does change throughout the contact. I doubt you had too much gain, as those I know that make those contacts do so with Yagi/Beam antennas with gain over 11dbi. I would guess you were slightly off frequency on the receive, but on the marker on transmit.
I know my IC9700 has an auto tracker than can track the received carrier and adjust as it moves with the Doppler shift, but I don't think any other radio has that. Others use the computer to adjust on the fly.
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I found it. It only "doubles" the range in 1 direction, and they use 20' of separation which gives 47dB of isolation. It is not bi-directional, so it is kind of a pain in the rear, and won't help most situation, but what do you expect from license-free solutions.
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40 minutes ago, Lscott said:
That was exactly why I asked the question. I've read some archived posts talking about various digital modes where people are singing about how great they are, except they forget about the practical aspects. So if FHSS radios are so great what if one wanted to expand the range beyond a mile or so they would need a repeater. Oops, not going to happen. Looks like they might not be a great recommendation after all. I just wish people would think a little bit more about the practical ramifications and implementation requirements more. When that's done you just might discover the digital mode you thought was the greatest thing since sliced bread, and better than anything else out there, just isn't a good fit while another mode would be better suited for the application.
I think any implementation would have to come from Motorola directly, or whichever FHSS radio manufacture you are using. That being said, lets talk about a theory that might work as a repeater.
My understanding is the radios utilize at least 50 frequencies, and hop about 50 times a second. The privacy is caused by changing up the hop set (order and number of frequencies), which means any repeater would have to be programed identically to the radios, but that's not a problem, that's typical of repeaters. Two problems exist, which we have to overcome:
1) At any given time (snapshot), the radios are using a single frequency for both receive and transmit. This could potentially be overcome by having a small delay in the re-transmission, say 2 hops behind the transmitting radio. Any radio in range of the transmitting station would continue to sync and receive from that station, stations outside that range would instead be synchronized and receive from the "repeater" station. Problem solved?
2) Second problem is, a traditional repeater usually has a fixed frequency set, and uses a duplexer to separate receive from transmit to eliminate desense in the receiver. The alternative is two antennas. Since 902MHz is such a high frequency, vertical separation can be relatively small and provide good isolation. 1 foot vertical provides 27dB isolation, and 2 feet increases that to 39dB, more than enough decent selectivity can overcome.
Make sense? I think the theory would work, practice might be a bit harder to accomplish. There there is getting 15C certification for the "repeater".
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52 minutes ago, Lscott said:
Here is a real question. Who makes a practical and affordable FHSS repeater? I did a search and didn't really find much of anything. If the radios are only usable for short range communications because there is no infrastructure to expand the range sort of takes the shine off the attraction to FHSS radios as a general communication tool.
I just tried to read through the rules (15C), and I don't see this being permitted. They even went as far as limiting the power, antennas and the gain on any antenna in an attempt to limit range. Also, I don't see how this would even work, its not operating on a frequency split, so it would have to be a store and forward type repeater, which might make the receiving stations hear the transmitted message twice.
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13 hours ago, WRQX963 said:
If I had a good rooftop or tower and $$$ were no option,
I personally like D-star on 23cm, 1.2GHz...de Always Itching 4 It.I have 1.2, the base has D-Star, the HT does not. 900 is less expensive to get into.
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Considering how empty the 902 ham band is, run P25 and nobody will hear you anyways.
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The FAA has a notice criteria tool: https://oeaaa.faa.gov/oeaaa/external/gisTools/gisAction.jsp?action=showNoNoticeRequiredToolForm
I have had to file notice for buildings and even substation power lines before. I have also used that tool to prove buildings are not tall enough to extend into FAA airspace.
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30 minutes ago, Lscott said:
The above is true. However they need to get the certification just once for a design. So long as they don't make any significant changes the certification applies to other models. I've seen that with some of the commercial Kenwood radios. The FCC ID for their P25 and NXDN radios, TK-5220/5320 and the NX-200/300 for example, are the same.
https://comms.kenwood.com/common/pdf/download/TK-5220_5320_Specsheet.pdf
https://comms.kenwood.com/common/pdf/download/02_NX-200G&300GBrochure.pdf
I am going to guess the cost of the certification amortized over a large fleet is rather small. The testing done for Part 90 the results likely could be just dropped into the submission for Part 95 except where there are specific differences between the services. The additional tests, if any, I can't see being that huge of a burden.
I suspect the real reason has to due with the rule changes in 2017/18 that disallowed businesses from applying for a GMRS license. With the rule changes the FCC effectively killed the business market for GMRS. In that case I can see why the main stream manufactures walked away. The paperwork and testing changes IMHO was a flimsy excuse.
My understanding is they want to see the testing to include more points directly in the GMRS range, which typically is not included in the wide range part 90 testing.
The secondary part is they probably don't want to deal with the whining and support to the typical licensee with the programming software. The usual cast of characters that whine when they have to downlead the free software/driver from the web to use the cable provided in the box and program their radio couldn't fathom paying a few real bucks for the correct cable and software.
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26 minutes ago, Lscott said:
IMHO I don't think they cornered the market as much as the main stream manufactures simply abandoned it. The main stream manufactures likely have higher profit margins on their commercial gear and don't want to get involved in the cut throat consumer market where the prices do nothing but drop. Government agencies and business have a lot more money to spend than the average Joe-six-pack. That's where they do the bulk of their business.
The only reason main stream manufacturers abandoned it is the changes to get part 95 approval. When a radio gets Part 90 approval for 403-512MHz, they used to be able to fill out one form, and use the existing test to get Part 95 approval. Now, they are requiring a entire second test and full set of submission to the FCC. For the percentage of the market that GMRS is, they all said no thanks and walked.
Heck, similar can be said for Part 80 (marine), but manufacturers will apply for that one because the market is much bigger than GMRS. There are many commercial radio needs for Marine service radios with IS ratings (XPR7550e comes to mind).
EDIT: For what it's worth, if it gets tested and approved in Part 90 for a block of frequencies that include the GMRS set, I see no reason it shouldn't be allow to get Part 95 on the same test. Granted, it may be stuck at narrowband, but that's still better than having to run another test.
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59 minutes ago, WRQJ277 said:
What confuses me is you can have 50 watts out of back of radio but when u run say 500 feet of coax say (LMR400) your power would only be about 20-25 watts to antenna.so how do repeaters over come power loss in the system?
I would love to know the true answer to this.
Because it would be better the 50 watts is going into antenna since that is the last component of system before signal goes into air.
When you are up at 1500 AGL, often times the entire repeater is cabinet mounted that high on the tower, with a very short coax run.
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4 hours ago, wayoverthere said:
On the laptop (basic Intel i3, 64 bit Win10), I did the both the CPS install and the Drivers install under an administrator account, and tried running the CPS both normally and as admin...got Error 1646 both ways.
The other computer is a Intel compute stick, with 32bit Win10; that one loads the CPS, and Windows is seeing the radio (I did the 'uncheck the boxes' in the network settings indicated in Motorola's instructions), but gives me a message to check the cable when I try to read from the 6580.
On the radio side, it does give me a message about 'IMPRES accessory connected' but I don't know if that says anything good and bad for the cable (which is from bluemax49ers). Going to try the 6550 later today if I get a chance, and see if I get the same message.
Yep, as admin.
Check the pins, and rub all the dirt off the contacts on the radio side.cn
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2 minutes ago, gortex2 said:
Wasn't aware it had that certification....I have a box of them someplace from an old public safety system. Only drawback is its in band. If your on GMRS CH20 and use a LP CH1 maybe you wont bother the mobile but most in band stuff causes issues.
True, but if you turn it down to 1W, and use physical separation of the two RF decks, good commercial equipment should have enough selectivity to have no issues when the VX1000 is on 1-8 and the radio is on 15-22.
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Another option, the Vertex VXR-1000 "in car repeater" has Part 95 approval, and you could connect it to the back of your commercial radio's DB9/25 connector and have HT access to your base station throughout the house.
- wayoverthere and gortex2
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3 hours ago, gortex2 said:
Remotes or dual head setup is what you want. In reality you could just put a speaker in one room. Anyway as said you can't have 2 radios able to TX on one antenna without a control station combiner. You could install 2 really good antenna systems for the cost of one control station combiner and not have the 6-12db or more loss.
AGREED! A TK-890with dual heads sounds like a good option
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I'm going to say, this is possible in a very limited capacity, if you are to use a single SIMPLEX channel on each radio, and they cannot be the same, you could then possibly get a full 6 can duplexer to work.
What you are really looking to do should be done with a single RF deck commercial radio, run dual heads, and enable dual watch/priority watch.
On second though, I found what you are looking for, a T/R switch: https://mfjenterprises.com/products/mfj-1708b-sdr (this one doesn't work well in the UHF commercial band)
You would have to choose which one to use to listen, and the other would be the receive & transmit radio. You CANNOT switch between the two without disconnecting and reconnecting coax.
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18 hours ago, WRQX963 said:
Let us combine the two:
Digital voice would work nicely on the ten meter repeater channels.There are supposedly a group of guys that are doing 10M YSF on the 991As, and I would love to try D-Star on on 10M, just haven't lined up the time with anyone yet.
On the commercial side, there are a few VHF-Lo band repeaters, one based off Kenwood's NX5xxx lol band deck, supposedly will do P25 and NXDN.
I'd love to put up a 10M digital voice repeater.
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2 hours ago, MichaelLAX said:
What does 10 meters FM, during a band opening, sound like to a distant station?
Like FM radio. A few weeks ago while listening to the 10m opening, I heard a guy loud and clear from Alaska who was supposedly running 50W. If you didn't know better, you wouldn't be able to tell it was 10M
What Is More Important To You In A Hand-Held?
in General Discussion
Posted
Why compromise and select 1. Sure, getting everything costs more, but in my experience, its worth it. You also forgot selectivity/sensitivity, which is hugely important. Don't forgot availability of support locally. That's not even starting a discussion about uses beyond GMRS, which may or may not be important to others.