Kenwood 900MHz Solar Site

Remote location solar repeater sites are nothing new; they have been around for many years. Puyallup Ridge located near the base of Mt. Rainier in Washington State is the location of the 927.5250MHz, QT 114.8Hz, repeater which is a unique 900MHz repeater solar setup!

The repeater site consists of solar panels and a battery bank that is shared by state agencies. With the 900MHz repeater site sharing power with state agencies its power consumption had to be low with a small footprint. Gene Colson, W7UVH (SK) built the Puyallup Ridge repeater many years ago and I thought it would be interesting to share it with others. While the repeater itself is not the work of art that a lot of Genes' other repeaters were, the repeater itself "function" is a work of art. The Puyallup Ridge repeater site has an extremely low noise floor so that makes this repeater even better!

The repeater power source is fed off a 13.8Vdc bus that terminates in a power strip. The 13.8Vdc power strip supplies the repeater PA, radios, and repeater controller.

The repeater receiver is a Kenwood TK-431 handheld with the receive filters changed out for ones centered at 915MHz (see "TK-431 Filter Changeout" for the details) that cover the 902.5250MHz input frequency. Since the TK-431 handheld is normally powered by a 7.2Vdc battery a dead battery with the cells removed was reconfigured with power leads and fed by a NTE935 adjustable voltage regulator adjusted to 7.2Vdc. The receiver uses a Advanced Receiver Research preamp, and is fed from a Sinclair Res-Lok duplexer.

The repeater transmitter is a high power TK-931HD running 20 Watts output. There is a cooling fan mounted on the radio if it should get too hot.

The repeater amplifier is a 800MHz, 155 Watt, Decibel Products (P/N:585-0684-009) amplifier modified for 927MHz with the first 2 RF stages bypassed. Cooling fans on the front of the amplifier are original and RF switched.

The above configuration is somewhat unique in that it uses a Kenwood TK-431 handheld radio as a low power receiver. The other unique feature is that that the Kenwood TK-931HD transmitter will go to sleep (shut off) when there is no use for 10 minutes. To wake the repeater up, it takes a 2 second key-up on the users' part for the initial wake-up and then the repeater "wakes-up" and powers on the TK-931HD which will stay on until there is no activity for 10 minutes and then the TK-931HD is powered off again. The only active current consumption of the Puyallup Ridge 900MHz repeater is the repeater controller, "wake-up" circuitry, and the Kenwood TK-431 receiver- this allows for a repeater that has very low current draw when inactive.