The AM Forum

Daughter Anna and I traveled north to the Chicago area today and dropped off a restored HT-30 (and picked up another one that I will keep) and then drove to nearby Batavia where Rob K5UJ was an excellent host at Fermilab.  I will post some photos and Rob can chime in and explain what is in the photo :)  Rob also provided me with a couple of 4-1000A tubes but all we could do was look at the REALLY BIG spare tubes at Fermilab.

And some RF hardware!

And the final 3.

Thanks Rodger; I told Rodger that camera he has takes really good pictures when I am not in them  ;)

The tube he mentioned is a Burle 7835 triode that is water cooled and is used by us to generate RF to accelerate proton beams.  We operate them in class C at 200 Mhz in 2.5 mw pulses of 20 / second.  The equipment in his photos except for the klystrons is associated with the 7835.   I actually don't know much more than that off hand, but the data sheet is on-line here:

www.burle.com/cgi/byteserver.pl/pdf/7835.pdf

Hi Rob,

I trust that you are doing well. It has been sometime since we last spoke.

I did not know that you worked for Fermilab. Could I ask what your position is with them? If I recall correctly, Fermilab is run by the DOE.

That looks like a pretty intense RF source, and it appears the rig was built by Continental Electronics. You just have to love that ultra-cool CE logo that Continental affixes to the front of their xmtrs. Thanks to the generosity of Bill, KD0HG, I have one of those CE logos currently residing in my shack; Bill had graciously removed it for me from a 50 KW Continental AM BC rig that had been removed from service.

Great photos!

73,

Bruce

That is some tour! I love the 4-1000. I don't mind supplying the screen at all.

Hi Bruce,

I'm doing FB.  I hope you are making progress on your mast issue.  I am an IT guy at FNAL.  This is why I am somewhat unknowledgeable about the RF areas.  We are managed by a contractor called Fermi Research Alliance LLC, which is a consortium of univiersities.  FRA has a contract with the DOE to operate the Lab. 

You are the second person I have heard of to get one of the big Continental badges.   That is some "bling" you have.   Several years ago one of the guys in the linear accelerator here retired and got one as one of his retirement gifts. 

<<<That is some tour! I love the 4-1000. I don't mind supplying the screen at all.>>>
It's a great tube isn't it.   Probably one of the cheapest 1 kw dissipation tubes there is, second hand, although I have heard prices are going up?  I got lucky last year finding a ham in Iowa who had around 9 pulls from old Iowa State Police VHF rigs and he sold them to me for around $35 each.   So far they are untested but for that price I didn't mind getting all of them.   I hope they just need to be lit up for a while then brought up slowly with ~ 1 KV and 150 or so ma Ip to get some color on the anode and degas them.

Rob, how interesting and impressive that you are affiliated with the Fermilab!

I drove past it many times during the late 1970s. During the period when I was baby-sitting WMAQ's AM-FM-TV xmtrs, my daughter and son-in-law were engineers at Bell Labs, I believe at Naperville. They were living in Batavia, where my oldest grandson was born, so on our treks to Batavia we saw the Fermilab, but never had the opportunity to tour it. Lucky you!

Walt

Now I remember why I left the Chicago area....too damn flat! My one fond memory of Batavia was finding a near mint 49 Mercury coupe that had been customized in the 50's and shortly stored. This was in 71 and I lived in Roselle at the time where the house was right under an O'Hare approach pattern.

Walt, thank you very  much.  You are very kind.  Yes we had a going operation at Bell Labs here, later called Lucent, then in the tech.stock meltdown about 10 years ago Lucent dived down in a big big way, and they laid off all but about 100 people over there and now I don't know if there's anyone still over there or not.   It may be that the whole thing has been consolidated at N.J.  

Up until a few years ago it was possible to drive behind a supermarket next to the 670 tx site over in Glendale Heights and park, get out and get right up to the fence around the station property.  It probably bordered the ground system.  You could get a good look at the feedpoint, guy anchors etc. and it was a pretty impressive stick being at 190 degrees on 670.  I think the supermarket closed and the property is inaccessable now.  It's always impressive and amazing to see something that tall on an insulator with the guys holding it up.   I think they were the last 50 KW in town running an old rig as their main, a 317A but they went solid state I think around 5 years ago or so.

p.s. I enjoyed seeing the photo of your dad you put up the other day.   He had an impressive station.  If I ever have such an AM station I want to be photographed in it wearing a suit and tie.  Probably the only time I'll put one on.


Ha ha, give me the flat land any day Carl!   My brother lives in western N.C. and driving through those mountains is for the birds!   I like a nice flat radio horizon, but the flat land wx can be a problem.   There's a forest preserve and park that runs up near one end of the long O'Hare runway, so if you are there on a nice sunny afternoon you have 747s coming in right overhead which is unnerving if you are not used to it.  

Rob

I was driving about a mile away when one of those DC-10's crashed on takeoff.

The office was right across the highway on West Higgins so it was noisy there, at home, or my many flights in and outta the damn place on business. Give me the relative peace and quiet of NH any day.

Weather sucked, we were the last house in the development and nothing but wide open fields to the SW thru NW. Had a mini tornado come between the house and garage, missed both but destroyed the pool and then hopped up before coming down again a few miles away and doing minor dmage. Wife went damn near mental but I was laughing. Id spent almost 16 months in Kansas with the Navy (dont ask  ::) and experienced 2 tornado seasons up and personal.

Carl

I guess every place has its pros and cons.  One thing I forgot to brag about here is our ground conductivity, but Iowa beats us. 

Elevated radials work well over poor ground and take less effort ;).

I didnt use 160 back then and a 90' tower with 3 slopers did OK on 80. The tower hole was about 2' of black earth and then sand, maybe it was a beach millions of years ago ;D

I was back to Roselle last year and visited our old neighboors who havent moved, the man of the house just retired from Lufthansa where he worked since he was 19. The field is now only a few hundred feet to a Interstate interconnect and noiser than the planes.

They probably take less wire too!   The sand was either a beach or more likely had something to do with glaciers. 

If you had checked with the village of Roselle about towers I'll bet you would have found out that things have changed since you lived there.  Just about all these suburbs have made it real difficult to get a decent tower up.