Which tests to run on possible faulty MDS 9790 radio

Discussion in 'Wireless & RF Design' started by BucSox79, Jun 2, 2009.

  1. BucSox79

    Thread Starter New Member

    Jun 2, 2009
    Hey all. Have a few questions regarding radio testing.
    My company does some work in the SCADA field. One of our customers uses MDS radios to pass data. In particular, a GE MDS 9790 transceiver.
    The 9790 is the Master radio that communicates with numerous remote radios in the 900 mhz range. The remotes are connected to RTUs.

    These master radios are redundant, two radios in each unit. If one fails, the other will take over. Last week a master radio was experiencing very poor performance with all remotes it communicated with. Logging into the system, everything was just slow and performed poorly on both radios in the transceiver. I checked the cabling, power out and it looked fine. The antenna line was also checked with an Anritsu.

    When I swapped out the entire transceiver with a new spare unit we had, everything returned to normal. Communications was no longer slow.
    I brought the radio back to our office and checked it out a little bit. Everything seems fine at first glance. I can communicate with a remote radio set up in our office, though that is far from normal real life scenerios.

    I was suggested to put a variable attenuator on the line and increase the attenuation and get the signal down to -100 rssi. Then check to see if the software would notice the actual drop in RSSI.
    What other tests can I run to verify the radio just didnt have a hick up? If there is a problem with it, I would think its in the diplexer or combiner board. Any ideas would be appreciated. Thanks.
  2. ethan007


    May 11, 2009
    Even we conduct this type of teat only. Hence I'm sorry but no idea. If you find it do let me know.