Retevis RT97S Repeater

[LeoG]

The only reason for me not to play with the internals is the warranty.  If it was out of warranty I'd be in there like nothing.  And I do agree that it's unlikely that the duplexer has slipped.  And what I mean by that is one of the adjusting screws got loose during shipping and has been slowly moving taking the duplexer out of tune and bringing the receive/transmit ratio out of whack. 

This repeater shouldn't be able to output 8.5 watts from the duplexer.  And the wattage shouldn't have increased since I tested it at the beginning.  I've double checked with a couple of HT which I marked their output wattage on the inside of the battery compartment when I got them, and they are the same as before.  Tells me the power meter is still working right.

[SteveShannon]

1 hour ago, LeoG said:

The only reason for me not to play with the internals is the warranty.  If it was out of warranty I'd be in there like nothing.  And I do agree that it's unlikely that the duplexer has slipped.  And what I mean by that is one of the adjusting screws got loose during shipping and has been slowly moving taking the duplexer out of tune and bringing the receive/transmit ratio out of whack. 

This repeater shouldn't be able to output 8.5 watts from the duplexer.  And the wattage shouldn't have increased since I tested it at the beginning.  I've double checked with a couple of HT which I marked their output wattage on the inside of the battery compartment when I got them, and they are the same as before.  Tells me the power meter is still working right.

Then the other thing to try is to connect a handheld to the antenna cable and see how the antenna works without the repeater and duplexer. 
I would just keep eliminating things until you eliminate the problem. 
Is the antenna even with the heavy part of the tree canopy?  Maybe it’s just being blocked. Try putting your antenna lower again. Vegetation will definitely block UHF. 
 

[LeoG]

So on Tuesday I brought the repeater home with me.  I have it set up in my truck with the Nagoya UT-72G mobile antenna, the squelch of the repeater is at 1.  I had given a friend one of my HTs and he lives 3120 feet from my house.  We were able to talk simplex from the HTs without any issues.  There is a large building and some trees in the way, some of the distance is over a river.  I'm probably 40 ft higher up than he is.  Then I walked about 1000 ft farther, 4190 ft and reception was still clear.  I then went in front of lots of buildings, houses, trees etc as I went from one block to another.  Transmission got worse but still legible enough.  As soon as I got to the next block the road gave me a clear shot to him and the reception was 90% quieting.

So the next morning I put the truck with the repeater up the hill to the highest spot near my house and we tried to chat through the repeater.  I could activate it but he couldn't.  We could talk simplex with the HTs.  I went up to the truck and used the repeaters microphone and he could hear me.  But he couldn't activate the repeater.  I set up the codes before I gave him the radio so I knew it worked already.  When I got about 600-700 feet from the repeater even I was having a hard time getting it to work right.  Then I used the mobile antenna attached to the HT and was able to talk with him without issue.  Pretty much proved to me that something is wrong with the reception of the repeater.

Now come today.  I brought the repeater back to the shop and started to play with the programming.  Tried a bunch of stuff and took many trips to see how far it would go.  Still only getting about 1/4 mile before I can't trigger the repeater.

And then I decided to try something.  I had asked Retevis what the Embedded Programming was on the edit tab of the programming software.  They told me it was for putting a note into the machine.  Recently I had put my initials and the date I received the repeater.  I decided to erase this and leave it blank.  Well low and behold that got me back to where I was originally.  Almost to my house and still able to trigger the repeater.  I tried putting the words back into the embedded programming and it screwed it up again.  I tried changing the machine function from 400M-520M to 450M-520M and that was a mistake.  Now the repeater had zero output.  I had this happen before but it was just random.  I don't know what I did, but screwed around a lot and then I was able to get 1.5 watts out, weird.  Took a while and I was able to get it to do 5.3 watts out.  And then played more and more putting random things into the embedded programming and finally got it back to 7.8 watts out.  I've got to tell Retevis that the embedded programming affects the wattage output of the repeater.

I still think the repeater is very quirky and inconsistent.

So tonight I set up the repeater in the truck and put it up in the same spot and I was able to walk out about 9/10ths a mile up the road with 2 radios and was able to connect to the repeater and had good modulation and quieting up to about 3/4 mile.  At 9/10ths it was still ok modulation but quieting was about 20-30%.  And I still had to walk home LOL.

So I think I got it back in operation and I believe the whole problem was the misinformation Retevis gave me about the Embedded Programming.  You can't use that to put text into the machine as far as I can see, it screws with the repeater receiver.  I never had issues with the transmitter.

So now I'm going to have to play raise the antenna higher to see if I can get more distance out of it. 1.5 miles is just unsatisfactory.

[WRFP399]

I don't know the terrain or topography you are working with but your results are definitely not great and I can understand your concerns.

I just wanted to drop a comment in here that I have two RT97s running out in the weather for 2 and 3 years now. Each of them gets range in excess of 20 miles, but I have height working for me as they are placed on mountain tops. Neither have had issues with water ingress of the RT97 itself or the LMR240/400 knock off cables feeding the antennas. These units are just strapped to back of 60 watt solar panels, no additional housing. All my coax connections are type N. I swapped out the "UHF" connection on the RT97.  I covered each connection with self-fusing rubber tape (3M Temflex 2155) and Scotch 33.

https://www.homedepot.com/p/3M-3-4-in-x-22-ft-Temflex-Splicing-Tape-Gray-2155/202195401?source=shoppingads&locale=en-US&pla&gad_source=1&gclid=CjwKCAjwjqWzBhAqEiwAQmtgT71-nMAnjU6Cg_oDfWybhJEd8tsCk2MJwSLI8WmaK9KsCCLlJKqNjBoCDGsQAvD_BwE&gclsrc=aw.ds

 

I posted this hoping to provide some encouragement. 

[LeoG]

Well if you go back to this post, at the bottom of the post you can see what I am dealing with for terrain.  And it ain't no mountain top.  I wanted to use the shop because it's up 100 feet more than my house is.  And I still have a line of trees near my house.  But I'm not surrounded like I am at the shop.  Never really realized how much forest I had around me til I started this project and then looked at google maps to see what was going on.

 

[yqtszhj]

Just for info, I had the watts increase on my RT97s from a little over 6 watts to 7.5 watts after having it powered up for a couple of weeks. so my experience is the same as yours. 

 

Also interesting to read about your embedded message experience. As far as Retevis support, I’m not too impressed for reasons that I won’t go into. My experience was you might get a answer to a simple question, but any real technical question or have a problem and it gets a pull a rabbit out of the hat answer. Good thing I didn’t ask anything important. 
 

That said, so far I love the repeater and it works well. The antenna, well that was another story.

[LeoG]

14 minutes ago, yqtszhj said:

Just for info, I had the watts increase on my RT97s from a little over 6 watts to 7.5 watts after having it powered up for a couple of weeks. so my experience is the same as yours. 

 

Also interesting to read about your embedded message experience. As far as Retevis support, I’m not too impressed for reasons that I won’t go into. My experience was you might get a answer to a simple question, but any real technical question or have a problem and it gets a pull a rabbit out of the hat answer. Good thing I didn’t ask anything important. 
 

That said, so far I love the repeater and it works well. The antenna, well that was another story.

Interesting.  So at least I'm not alone.  I've sent several emails to them and the last couple have been ignored.  So like you I'm not exactly impressed.  As for the antenna I can say it produces a great SWR over a broad range of frequencies.  So they are employing some sort of "circuitry" system to do that I'm betting.  When I apply a DC current using my ohm meter it acts strangely.  Like some resistors/impedance and capacitors are in the system.  I just checked their RG58/u cable and it seems above standard for loss.  But it's still RG58 and lossy.

When I was screwing around I switched the "machine" from 400 to 450-520 and I couldn't get any power out of the repeater for a while.  Hmmm....  I wonder if I had to power it down after the change.  Because I did do that but I don't remember if that when things came back to life.  But when it did come back to life it was only 1.5 watts out.

Very strange and very inconsistent.

[LeoG]

Funny, I just checked my email and there was a message from them.

 

They asked what is the codeplug for the walkie talkie I'm using.  I have the TD-H3s and have no idea what a codeplug is.

[SteveShannon]

7 minutes ago, LeoG said:

Funny, I just checked my email and there was a message from them.

 

They asked what is the codeplug for the walkie talkie I'm using.  I have the TD-H3s and have no idea what a codeplug is.

A codeplug is simply a dataset that’s built with a computer and uploaded to a radio with settings for channels and other configuration information.

As i mentioned before your DC meter tells you almost nothing about an antenna or feedline unless it has an intermittent short or open. It’s like hooking a paperback book to your car’s diagnostic port. Most antennas have impedance at certain frequencies due to inductance and capacitance, but that means nothing at DC.

[yqtszhj]

1 hour ago, LeoG said:

Interesting.  So at least I'm not alone.  I've sent several emails to them and the last couple have been ignored.  So like you I'm not exactly impressed.  As for the antenna I can say it produces a great SWR over a broad range of frequencies.  So they are employing some sort of "circuitry" system to do that I'm betting.  When I apply a DC current using my ohm meter it acts strangely.  Like some resistors/impedance and capacitors are in the system.  I just checked their RG58/u cable and it seems above standard for loss.  But it's still RG58 and lossy.

When I was screwing around I switched the "machine" from 400 to 450-520 and I couldn't get any power out of the repeater for a while.  Hmmm....  I wonder if I had to power it down after the change.  Because I did do that but I don't remember if that when things came back to life.  But when it did come back to life it was only 1.5 watts out.

Very strange and very inconsistent.

It’s good that you got the correct antenna. They sent me the wrong antenna. I ordered the same package as you and received the MA02 dual band ham antenna and not the MA09 Gmrs antenna. It had a SWR of 4.21 and my VNA showed it tuned perfectly for 430 MHz. I sent them pictures of this and they told me it was the right antenna and that 4.21 was good enough. Then they told me my test were invalid. I went back and forth with them but eventually just disassembled the antenna and tuned it for Gmrs but I shouldn’t have had to do that. They never admitted they did anything wrong. There’s more to the story you just wouldn’t believe but I’ll stop now.

 

Still love the repeater though. Just sharing this so hopefully others won’t have the same experience.

[LeoG]

1 hour ago, SteveShannon said:

A codeplug is simply a dataset that’s built with a computer and uploaded to a radio with settings for channels and other configuration information.

As i mentioned before your DC meter tells you almost nothing about an antenna or feedline unless it has an intermittent short or open. It’s like hooking a paperback book to your car’s diagnostic port. Most antennas have impedance at certain frequencies due to inductance and capacitance, but that means nothing at DC.

Thanks.

 

And yes I realize that.  But the way the meter reacts tells you something of what the circuitry might be

[LeoG]

16 minutes ago, yqtszhj said:

It’s good that you got the correct antenna. They sent me the wrong antenna. I ordered the same package as you and received the MA02 dual band ham antenna and not the MA09 Gmrs antenna. It had a SWR of 4.21 and my VNA showed it tuned perfectly for 430 MHz. I sent them pictures of this and they told me it was the right antenna and that 4.21 was good enough. Then they told me my test were invalid. I went back and forth with them but eventually just disassembled the antenna and tuned it for Gmrs but I shouldn’t have had to do that. They never admitted they did anything wrong. There’s more to the story you just wouldn’t believe but I’ll stop now.

 

Still love the repeater though. Just sharing this so hopefully others won’t have the same experience.

I have to get my antenna up above the tree line.  And then I'll have a real report.

[LeoG]

Got a different mobile antenna.  I was running the Nagoya UT-72G and I picked up the Midland MXTA26 to see what that might do for the repeater.  With the Nagoya I was able to get 0.9 miles with the OEM antennas on the TD-H3s.  I brought two of them with me and had to get about 50-100 feet away from each other to talk to myself.  Did I mention it's no fun playing walkie talkie by myself? LOL

Then I picked up a pair of the Nagoya 771G antennas and did the same test a few days later and was able to get 1.3 miles out.  I also have a pair of Smiley rubber duck antennas that I didn't test with the Nagoya UT-72G on the repeater.  When I was using the Nagoya with the repeater I was able to push 6.4 watts into the antenna with an SWR of about 1.24

I put the Midland MXTA26 on the truck and did the SWR test and got a 1.01.  The repeater was pushing 7.8 watts into the antenna.  I took my walk using the Nagoya 771G antennas on both radios and passed the first hurdle at 0.9 miles and it was still clear sounding, quieting about 75-80%.  With the OEM antenna it was scratchy and crackly.  I went out to 1.3 miles and quieting was about 70% and voice was still clear.  I tried the Smiley antenna on the transmitting radio and it seemed to work about the same.

So I kept walking and got about 1.5 miles out and the Smiley antenna wouldn't connect with the repeater anymore.  Changed over to the 771G again and back in business.  I made it out to 1.8 miles which is nearly to my woodworking shop and I had to place the radios about 100 feet apart from each other before I could get the receiving radio to hear the repeater.  Desense is hitting hard now with the 5 watt radio being so close to each other and the repeater being nearly 2 miles away.  Scratchy sound 50% quieting or less, breaking up a bit but that could have been the desense.  Was far enough from the receiving radio it was difficult to hear it easily.

I was going to walk until it failed which I'm sure would have been pretty soon when one of the renters in my building just happened to be driving by and pulled up and asked if I needed a ride.  Hell ya, so I was able to get a ride back instead of needing to walk back.  Made my night.

So the Midland MXTA26 was a good improvement over the Nagoya UT-72G.  Same with the 771G vs the Smiley rubber duck over the OEM.  Both giving improvements over the previous.

It's a pretty clear path.  Still lots of houses and trees in the way.  The repeater antenna was about 85 ft above sea level.  The 0.9 mile reference is at 128 ft above sea level.  1.3 mile reference is at 150 ft above sea level.  1.5 mile reference is at 157 ft above sea level and 1.78 mile reference where I ended the test is at 161 ft above sea level.  So all in all a 76 foot rise in elevation from the repeater start point.

[LeoG]

OOOOoooooooo K

I've been operating on RPT8 and CTCSS 100.0Hz on the repeater.  I noticed some morse code on that channel a few times indicating another repeater in the area.  It's very weak and likely out of range. But I can still hear it. 

So I dropped down to RPT7, same CTCSS and now I can hit the repeater inside my house.  On RPT8 I had to walk up the hill to hit it.  Now I can do it inside the house.  Ummmm.... why?

I did try to do voice but it couldn't pass it through.  But it really is significant that I could ping the repeater in the house on 7 vs having to go up on the hill to ping on 8.

And then we had some storms come through and wet everything.  I figured that might kill it off.  But I can still ping it in the house.

[OffRoaderX]

1 minute ago, LeoG said:

On RPT8 I had to walk up the hill to hit it.  Now I can do it inside the house.  Ummmm.... why?

My guess (100% GUESS) is that the duplexer is tuned better for Ch7.. I would not expect that much of a difference just one channel away but you should do some range-tests on all the different channels to see which one works best.

[LeoG]

In theory the repeater should be tuned to 467/462.550 because that's what the mini duplexer is tuned to.

Dropping down one station really shouldn't be that drastic.  Originally I started on RPT3 and had the same results as RPT8.  I've tried CTCSS and DCS tones and it didn't seem to make any difference.  I thought maybe the DCS might work better than true tones.

But I came to the same conclusion as you that I should at least try to go through the range of 8 channels to see if there is any difference.

[LeoG]

Just took a stroll outside and walked another 560 feet further from the repeater with another drop of 23 feet in elevation and was able to ping the repeater.

So now I'm that much farther in the shadow of the hill and still able to ping the repeater.

Gotta get that antenna up another 20 feet or so and I think this might be a thing.

[LeoG]

Ok, I'm starting to think there is an open repeater on RTP7 around here.  I don't need a tone to make it ping, and if I put a tone on it, it still pings.  Same with RPT6.

When I go on the other RPT channels I get no response.  So I'm going to try those now.

 

This is weird.

[LeoG]

So since I put up the antenna at my house I decided to try the repeater here.

So I could get out to about 4.6 miles and hit the repeater but the signal was weak.  I came in about 1/2 mile and the signal was much stronger.  Rode around town and checked out different distances.  Most of them were about 2-2.8 miles out and had a good connection just driving around with my mobile radio.  Anything within 1.5 miles was full quieting or close.  I went to the shop where the repeater usually is and was able to hit it and talk.  It was scratch because of all the trees.  But if I went out to the road it cleared right up because the trees are out of my way. 

So I suspect if I can get my shop antenna up above the trees it should do quite well.  The shop is on ground 100' higher than the house.

 

[Socalgmrs]

I’d say a better antenna with more gain would help dramatically.   What radio are you running that you only get a few miles?

[LeoG]

You really don't get that I don't live in a desert with no obstacles.  Everything around here is hills and trees.

The antenna is at 42' off the ground so 105' altitude above sea level.  I'm in the upper middle of a hill at 62' ASL and the top of the hill is at 85' ASL, so effectively I'm at about 20' above ground level.  The trees around here are 70' tall.

I'm obviously running the RT97S and that is outputting 7.8 watts into the coax.  I have a 1.92dB loss so it's 5 watts at the antenna and it's a 7.2 dBi (5.05 dBd) gain antenna so effective radiated output is around 15 watts.

I'm sure if I lived where you did I would be getting 30+ miles out of the repeater.  But around here you get 5-7 miles best case.  2-3 miles is the usual.  I want to get my shop antenna above the trees so I'll need it to be 70-80' above ground level which would put it at 170' ASL, still pretty low.

[Borage257]

1 hour ago, LeoG said:

You really don't get that I don't live in a desert with no obstacles.  Everything around here is hills and trees.

The antenna is at 42' off the ground so 105' altitude above sea level.  I'm in the upper middle of a hill at 62' ASL and the top of the hill is at 85' ASL, so effectively I'm at about 20' above ground level.  The trees around here are 70' tall.

I'm obviously running the RT97S and that is outputting 7.8 watts into the coax.  I have a 1.92dB loss so it's 5 watts at the antenna and it's a 7.2 dBi (5.05 dBd) gain antenna so effective radiated output is around 15 watts.

I'm sure if I lived where you did I would be getting 30+ miles out of the repeater.  But around here you get 5-7 miles best case.  2-3 miles is the usual.  I want to get my shop antenna above the trees so I'll need it to be 70-80' above ground level which would put it at 170' ASL, still pretty low.

For what it’s worth, your numbers seem reasonable given the vegetation and topography. 42’ agl would yield an ideal radio horizon of about 8-12 miles. Now if you could get the antenna 42’ agl at the top of the hill….

[LeoG]

Well I looked on google maps and found an ideal path for the signal and had to see if I could get it to work in real life.  It had a bunch of signal travel over the river and not a lot of dense forest.

Using a interactive topographical map the end point is 19 meters at ground level, it says I'm 21 meters.

It did pretty good, about 50% signal strength on the Wouxun signal meter in the truck.  Dropped off pretty quick after that.

I made a big circle to come back and I traveled over the river and I was surprised that I got almost nothing for a response.  Just random low power jitters.  Came back up the interstate and really didn't get a reliable signal until I was about 3.7 miles away.

And now I see why.  It's the hills...  My antenna is at 33 meters (21m+42')

Can't get through that 40 meter hill.

 

My shop is at 48 meters and then 60' of mast would put the antenna at 66 meters and I would be able to get past those hills.  Which is why I want to put the repeater at the shop.

[LeoG]

2 hours ago, Borage257 said:

For what it’s worth, your numbers seem reasonable given the vegetation and topography. 42’ agl would yield an ideal radio horizon of about 8-12 miles. Now if you could get the antenna 42’ agl at the top of the hill….

Which is why I want to set the repeater up at my shop which is 48 meters above sea level plus I need to put the mast at least at 60' to get above the tree line which would put me at 56 meters.

[SteveShannon]

Elevation relative to sea level is irrelevant.  AGL is relevant. Just express things relative to each other.