Information about Polevault
I’ve read some things about Polevault and how some folks said it worked so I thought I’d tell you how I remember it.
Polevault (Troposcatter Scatter) sites had four separate systems. Two south facing Transmitter/Receivers and two north facing Transmitter/Receivers. Each antenna was both a transmitter and a receiver. The transmitters had a power output of 10 Kilowatts continuous, so each site was constantly using over 40 KW of power.
The transmitters in each system were tuned to a different frequency between 650 MHZ and 800 MHZ approximately. Between the north/south transmitters was a spare transmitter ready for use in case either of the active units failed. If there was a failure an alarm would sound and the airman would run to the transmitter area. One person would shut down the failing unit while another would undo the rigid conduit U-joint (4" copper pipe with dielectric). When the transmitter was shut down he would then tell the man on the conduit that it was safe to undo the coax and remake to the spare transmitter. When that was done he would signal the other to energize the spare transmitter and increase the power to 10 KW. This was a rehearsed maneuver and could be completed probably in less than a minute or so.
Each of the transmitters was powered by an exciter which was active and had a backup for each north/south transmitter in case of failure. (they were quite reliable though)
Each system had two sets of receivers, one active set and one spare set, which required the most effort in maintaining their peak operation. They were tuned, tubes were constantly being replaced, crystals changed and just had hours and hours of efforts expended to keep them operating. The sensitivities required at Saglek was probably about more than the receivers were capable of delivering. Everyone was always pleased when they could say that they were finished with the required maintenance. It was never ending though and I think we probably wore them out.
The telephone switching gear and the teletype equipment was all located in one area and was primarily maintained by the Marconi rep who came from a telephone background. They also knew the transmitters/receivers but were mainly telephone guys. (one at each station).
There was an office area in Polevault #1 building and an equal space in Polevault #2 was used for parts storage and other dead storage required. Cases of World War Two vintage C-rations were kept there along with blankets and foul weather gear. It was often the opening of a case of C-rations and looking for the fruit cocktail, beans and franks, sausages, cigarettes, pound cakes that brought lots of laughs and trading between the guys. The C-rations seemed old (they were) but really only 15 years old at the time we opened them. The Pound cake was quite fresh when the can was opened. The Lucky Strike Cigarettes were in green packages and dry beyond belief. You had to really need a smoke to try one of those cancer sticks.
There was other miscellaneous equipment there which I can’t remember but we had a recording device for signal strength. Sgt. McGhee’s diary of the storm of September 1959 talks a lot about how the equipment was configured. In addition to the four dish antennas there was also two emergency horn antennas mounted atop Polevault #1 building which were about 5’ wide at their mouth.
We also had emergency power in the form of two Cat generators (I think) and we were trained in how to start them and get them on line if necessary.
As you may have noticed, I have also included a diagram which depicts the layout of the interior of our building.
Our thanks to Dennis Abbott for providing this detail and for his ongoing support of the Pinetree Line web site