Recommended Repeater Setup

Tyler

Member
I am working in Marin County which has many steep hills and somewhat rugged terrain. The typical area we work in varies from on the coast to up in the hills or between valleys (0 to 1,000ft elevation, typically). We are currently using the Triumph-LS, Triumph 1-M for our base, and the HPT435BT radio alongside our base. The external radio helps get signal in some pretty difficult areas but I think we might need a repeater to ensure that our base is always in a great location and we can get signal behind the hills that are interfering with the radio signal.

We were also thinking of potentially trying to use the 35 watt radio as a repeater instead of using it alongside the base to help us get signal in some of the more difficult areas.

What setups are you currently using and what has been working the best for you to optimize the usage of your Javad units?
 

Phillip Lancaster

Active Member
If I was you I wouldn't even use it beside the base really ever. I would always use it as a repeater. I know without a doubt that the 1 watt internal will reach over 4 miles on flat ground. In the hills just setup the repeater where you lose reception and may have to move it a couple of times to get the job done depending on terrain. I have set the base in an open area that was lower on the job and went about 1 to 1.5 miles away and set the repeater in a pine thicket on the top of a hill.
 

Duane Frymire

Active Member
Is there a way to raise the T1M radio higher or do you need the external radio to do that? I assume that's why one would use external radio near the base, just to get a bit more height and distance of coverage?
 

Nate The Surveyor

Well-Known Member
Isn't there an external antenna connector, for the T-1m?
My memory says there is. (Correct me if I'm wrong).
Maybe you could get a 5db gain antenna, with a 15' wire, and put the T-1m up on a normal tripod/bipod setup, and then extend the TX (transmit) antenna up 20' high, and with the 5db gain antenna. All this could extend range for the 1 watt internal, in the t1m.
With all that in place, you effectively have greater range, without a repeater.
And
Much more options for the locations of the repeater.
I'm just thinking out loud here. Of course, all this is based on the assumption that the T-1M has external ant. connector.
What say the big chiefs?
Nate
 

Larry Stevens

New Member
Nate,
The antenna for the T-1m is the pole between the tribrach and the T-1m. The connection from the T-1m to the antenna is in the center of the pole and connects when you twist it on. No other plug for the antenna.

Phil,
That makes a lot of sense. What is the procedure/directions for using the 35 watt HPT435BT radio as a repeater?

Thanks for the responses.
L
 

Tyler

Member
The spacing requirements as mentioned by Matt here: (http://www.javad.com/downloads/javadgnss/how-to/hardware/UHF_Repeater_Configuration_Example.pdf) needed for using the 35 watt radio as a repeater may hinder some of our ability to work on areas just on the other side of smaller hills. Would the HPT401BT be a better option for a repeater in this case? Ideally we would be able to set a repeater on the hill directly adjacent to the site of measurements below. A minimum of 800' seems like it would not allow us to take measurements at the base of the hill we have our repeater on in a lot of cases. Any thoughts on this?

The plus side of the 1 watt as a repeater may also be that it also has its own internal battery as Matt has mentioned in another post (https://support.javad.com/index.php?threads/using-the-t1m-and-35w-radio-as-repeater.2721/). Also there is a lot of good information on that post about setting up the radios as repeaters.
 

Duane Frymire

Active Member
Lots of good information above. Two more questions: first, does the full duplex 1 watt give much better result using as repeater; second, what is recommended separation if using the 1 watt?
 

Tyler

Member
I need to possibly setup a repeater for a project but the line of sight is not great. In your experience how much wiggle room is there for a clear line of sight when setting up a repeater. We are using the T-1 base and a 35 watt radio as a repeater. I have attached a path profiler of the area I am attempting to setup a repeater. The point on the east side of the photo is the base position and the second point is the best available repeater setup I could find. The third point is the desired area for the radio signal to reach.

If this does not seem feasible, how long should I setup the Javad LS unit over the desired points to achieve an accurate location using DPOS if there is not sufficient radio signal?
9137
 

Sean Joyce

Active Member
Tyler, looks like you work in some nice country in northern CA. Getting radio corrections through the second hill to the 3rd point is probably not feasible.
In regards to how much time you need on a point, I like to get at least 20 minutes or even more depending on how difficult the sky is over the point, and I try and come back and get another position for redundancy. Why not set another base near point 3?
 

Tyler

Member
Why not set another base near point 3?
That was a thought as well, but how can we ensure accuracy when jumping between different base locations? When we usually setup a new base location we will also go back and measure the old base position along with a few other common points. Is this unnecessary for having accurate measurements? Thanks for the reply.
 

Sean Joyce

Active Member
That was a thought as well, but how can we ensure accuracy when jumping between different base locations? When we usually setup a new base location we will also go back and measure the old base position along with a few other common points. Is this unnecessary for having accurate measurements? Thanks for the reply.
I like to have a common check between bases also, so yes you could set a check point from base 1 that you could also cross check from base 2, or with the receiver on base 2 go back and get a position on base 1 and process through DPOS and see how it agrees.
The checks that you perform are going to be what you feel comfortable with.
 
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