[AReU] Stuff for AREU in December

[Tony Stone]

Well according to the calendar, AREU is next Tuesday. 

I don't know what is specifically on the agenda but I have 
a couple of items to "show and tell". 

The first item is the ATV system that I have improved for continuous 
operation. Below is a general idea of my work on it. 

 I have finally ventured into the shop this weekend. I decided to 
 get the ATV transmitter cooled adequately to operate continuously. 
 I am using an Astron 20 amp linear supply. It becomes very-very hot 
 after about 5 minutes of operation at full power. The amplifier heat 
 sink cannot be touched after about 7 minutes of operation. I mounted 
 a 3 inch fan on the heat sink of the Astron supply and two 2 inch fans 
 on the top of the amplifier. I operated it for 1.5 HOURS this evening 
 with tolerable heating. I would not mind using the unit for continuous 
 service if I had put slightly larger fans on the power supply and the 
 amplifier. I am very happy with the results. 

The second item is some surplus Gunn diode oscillators that I 
obtained from George. 

The most interesting one was a cavitity with two active terminals 
and was connected to a good looking horn antenna. 
I looked up the manufactured on the internet and found that the 
unit was an X band Gunn diode oscillator with a mixer built into 
the cavitity and a horn antenna. It is used for a traffic motion 
detector at intersections. It is similar to the X band Gunnplexers 
sold by Advanced Receiver Research for 10 GHz wide band 
ham transceivers. I have it oscillating but I'm not sure it will pull 
down into the ham band. It is supposed to operate around 
10.56 GHz. The tuning screw is small and I don't have a feel as 
to how far it will tune the cavatity. 
There is another lower power Gunn oscillator. I have passed 
current through it and it exhibits the negative resistance curve 
but I have not been able to detect any output as yet. I think my 
old spectrum analyzer is not too sensitive at 10 GHz. 

Hope to see everyone at AREU next Tuesday at the Bell Shoals 
Baptist Church. 

73

Tony