backyard observatory

[cfz2882]

Decided to build a new backyard observatory-basicly a much better built replica of the one I had built 1982-83 as a teen:hexagon shaped,consisted of 3 stacked closed compartments and an open topped observation deck at top. Original version had shortwave radio listening post and parts storage on first floor,sleeping/lounge area 2nd floor,partly glassed in 3rd floor with good stereo setup,and the 4th open top observation area where the telescope(cheap Japanese refractor) was set up.Original was mostly built of mostly salvaged wood,corrigated siding,and was not insulated and not quite all the way leakproof New version will be mostly steel,insulated,and top deck may have retractable cap.Have much better telescopes now,a nice Meade one with computerized base bought in 2005 and a Coronado solar telescope also from 2005.

 

[tolivac]

I remember a few "backyard" observatories in Rapid City when I was there in the late 60's thru the early 70's.If you have a SW receiver-you can listen to VOA in Greenville,NC-or try.Can't give the frequencies here-but you can look them up online or from the World Radio TV Handbook-available in bookstores or libraries.Others are Radio World and Monitoring Times.these have websites.Remember a time when stargazers built their own telescopes from plans in Popular Mechanics and Edmund Science Co-also got the lenses and mirrors from Edmund.I remember a cheap reflector scope I received as a Christmas present and set it up in the backyard of our Rapid City house.As close to an "Observatory " as I was going to get.The humidsw air here makes gazing difficult.In the SD area-esp near RC-the air was dryer and made viewing easier.

 

[cfz2882]

shortwave receivers

the shortwave radios in the original observatory were a late-1930s Silvertone table radio and a ~1968 Philips stereo that had shortwave-didn't know much about shortwave antennas then,but still was able to pick up lots of interesting stuff When the new observatory is built,I have a nice 1968 US Navy receiver that will be installed-mostly transistor with a couple tubes,it quit on me a couple years ago-lots of densely packed plug in modules in the water resistant set,so finding the trouble will be quite an adventure...

 

[tolivac]

SW antenna-for receivers a long piece of wire will do.For transmitters at where I work-the antenna structures have to be seen to be believed.Low band antennas-under 11Mhz are about 500Ft tall and 500Ft square.High band ones about half that.Open wire 300 ohm transmission lines.Transmitter power 250-500Kw.When a bird lands on the lines-it explodes and momentarily trips off the transmitterVSWR trip.One time a pair of birdlegs made a Jacobs ladder of sorts.The transmitter just kept going.Look up VOA Greenville,NC and you can see where I work-Mid shift supervisor.The Jim Hawkin Radio World site has some good pictures of the plant and antennas,as well as the transmitters.Got to do a transmiiter antenna change---

 

[cfz2882]

VOA Greenville

I found some videos of VOA Greenville on Youtube-one was from 1998,some others were newer-cool!-In the 1998 video there were 3 old GE transmitters,a big Marconi one and another I don't recall the brand of My observatory construction is basicly stopped because of weather,but some of the electrical/electronic,HVAC,and audio equipment is being checked out and built.

 

[tolivac]

The VOA video you watched is the Greenville "A" plant-near "little" Washington,NC-Beaufort County.This site closed in 2006-was turned over to the state of NC.The last time I was there several years ago-to salvage parts for our sister GE transmitters at B plant-the walls at A plant were covered in mold.The HVAC systems were turned off.Only the tower lights on.The towers were demolished last year.Sad sight.I worked that plant for 1 year.They had 3 GE transmitter-250Kw,3 CEMCO 420A-B site has these as well-they could run at 500Kw with both RF power amps parralled.Only have done this twice.The other CEMCO transmitter is a 420B installed in 1985.Same with the Marconi.The Marconi was upgraded later with a solid state SSM modulator from CEMCO.Now parts of that were salvaged and are stored at B plant.B plant near Black Jack,NC is the only remaining US govt SW broadcasting plant in the US.Sadly the transmitters at A plant would now be scrap.Also there were 2 TMC SW sideband transmitters-40Kw these were used for backup program distributiuon to overseas plants.Only one CEMCO sidebander left-50Kw-needs parts.They are no longer available.We just hope the plant I am at-and the rest of us-will stay opened for awhile.Need about 3 years before I could get 30 yr retirement.These transmitters are 65,50,and 35 yrs old!Hopes for new ones are still with us.B plant is being upgraded-LED lighting,new switchgear-MV,LV-so there is hope.And new paint jobs.Transmission line poles being replaced.