Buying used Trimble equipment

> 1. Some have internal radios, some don't. What's the difference?
The internal radio. Other than that, not much.

> 2. 5700's seem to be used as a base station, can one use it as a rover too?
5700's can be used as a rover. It is a bit of a load to pack by modern standards, but it works fine. Trimble would sell a pair of 5700's as their RTK setup prior to c.2000, before they came out with the 5800. Then they sold the 5700 as the base and the 5800 as the rover.

There are 2 versions of the 5700's Zephyr antenna . One is a big dish, the other much more compact. I wouldn't want to try to use that big dish as a rover.

Keep in mind that 5700's & 5800's are GPS only. No Glonass. Also, I'm not sure if Trimble is still servicing (ie/ making parts for) those models.

> Hi, I was looking at some used Trimble gps receivers, 5700 and 5800. I have a couple questions:
>
> 1. Some have internal radios, some don't. What's the difference?
>
> 2. 5700's seem to be used as a base station, can one use it as a rover too?
>
> Any help in understanding this stuff would be appreciated. Thanks.

5700's are a bit bulky to be used as a rover. They utilize an external radio and are designed to be used as a base since they hang off the leg of a tripod and are not really pole mountable. The 5800 does have an internal radio and being pole mountable works well as a rover/fast static when coupled with the 5700. I have an old 5700/5800 combo with a Trimark 3 radio for RTK work. But, big but, it's GPS only, works well (in the open), but can't hold a candle to my R8 GNSS receivers for getting fixes in challenging spots. The cables are also a pain compared to the blue tooth used by newer receivers. I've retired the 5700/5800's to doing static work to augment my R8's for blunder detection. Another thing to consider with the radio is the recent FAA narrow banding requirements for radios. Make sure the radio is compliant.

If your looking to do production, GNSS is the only way to go. If you're only doing occasional work setting control out in the open for later occupation with a TS, the 5700/5800's will get the job done and the price tag is a whole lot easier on the wallet.

If your wanting to make the jump to the Trimble R8 modlel 3 I have a full RTK kit for sale. Email me for info.

Just to avoid confusion of the OP's question 1, some 5700 units (Rover's) DO have internal radio's, however, they require an EXTERNAL range pole antenna on the rover pole. At least that's how I remember it.

Another thing to consider with 5800's with internal radios is what frequency they receive corrections at. Some are 900 MHz and others are 450-470 MHz or something along those lines.

Gregg

You can purchase the small Zephyr 2 antenna which is glonass...there was a couple on Ebay...the regular small zephyr is L1 and L2 only, same as the Zephyr Geodetic for your base setup, also there are pole clamps for the 5700 to attach to a rover pole...I have 2 of those...
You can also use a TSCE data collector and cell phone for rover work...