triplegfarms - 3/27/2008 05:38

I have been using RTK for about 4 years now. But, we are very hilly and have lots of trees. I have 3 base stations and and move them around from farm to farm. I had a tech from John Deere come the other day to help me setup a network. He told me that some were using 5 watt power boosters. I am testing now with the radio up about 120 ft and can get good coverage for about 2 1/2 miles. I was thinking with more power it would help me blast the signal through some trees and such. I bought 6 db gain antennas also but have not installed them yet. Also I talked to my local radio shop yesterday and the tech looked at the FCC regulations for that band (902-928) and there are no power restrictions. I need to cover about 14,000 acres over about 32 miles from end to end. I was just thinking if some of you new a good brand or had used a particular one it would be helpful. Thanks for the replies.

djohnhill - 3/27/2008 09:42

Triplegfarms quoted...

"Also I talked to my local radio shop yesterday and the tech looked at the FCC regulations for that band (902-928) and there are no power restrictions."

In fact, there are many restrictions on the 902-928 ISM band in the US and Canada.

Ensure your radio tech is familiar with the FCC rules:

http://a257.g.akamaitech.net/7/257/2422/16nov20071500/edocket.acces...

Section 15.247 Operation within the bands 902 - 928 MHz
===================================================

(2) For direct sequence systems, the minimum 6 dB bandwidth shall be at least 500 kHz.

(b) The maximum peak output power of the transmitter shall not exceed 1 Watt. If transmitting antennas of directional gain greater than 6 dBi are used, the power shall be reduced by the amount in dB that the directional gain of the antenna exceeds 6 dBi.

Note the FCC view on external amplifiers for Part 15 transmitters:

http://a257.g.akamaitech.net/7/257/2422/16nov20071500/edocket.acces...

"Can an optional amplifier accessory for a Part 15 device be certified as a separate device under Section 15.204(b) ?

No, if the transmitter was originally granted without an amplifier, you must file a new application for the device and any transmitter/amplifier option, as stated in Section 15.204(b). In no case can the amplifier be authorized and sold separately, except, as allowed in Section 15.204."

Be careful about what amplifiers you use. If you start blowing your neighbors autosteer systems out of the field with boosters, someone may complain. There are fines not to mention the loss of your investment in equipment.

To go above 1 watt you may need to go back to licensed 450Mhz if you want to burn through trees.

Again, get an experts advice first.