TheRadioBoard

This year will be the fifth year for the annual summer homebrew contest. It runs from 12:01 a.m. local time July 22nd thru 11:59 p.m. local time August 6th. Hope you consider entering. We've seen some great entries over the years, and this year should be no exception. Details:

http://theradioboard.com/radiocontest/index.htm

Dave graciously put up a web page for it.

"Rob"

Hey Rob,

I am sure I will be in on it.


K

I'll be there. Currently trying to debug the receiver I'm hoping to have ready in time!

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Tom

allthumbs and Krystallo,

What type of sets are you guys planning on using?

Mine will be a shortwave set with a 6SK7 detector tube with a 6J5 doing audio duties. It's a choke coupled unit.

"Rob"

Hey Rob,

I am finishing up a two tank unit - 660/48 air core w/2 X 500 pf single gang grails and 660/48 air core w/ 4x 500 pf gang wiper less . The grails will be the ant unit and the wiper less will be "SOMETHING" - type 30 regen xtal set MFP 102 regen - or a combo of these- dunno what time will bring yet.

K

Rob, you can see mine in the tube radio portion of the forum, under "3-tube regenerative superhet" which I just posted yesterday. It's working now, although as yet I'm unsure of the band coverage. 30 m for sure, and perhaps as low as 49 m and as high as 16 m. I'll learn more this weekend.

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Tom

allthumbs,

Great looking set! Looks like it's working pretty well for you also. You are a true craftsman.

Krystallo,

Looking forward to seeing your set. Sounds pretty innovative.

Rob

Wow, this one's getting close ! No building going on here lately, so I'll have to pull one down off the shelf. Best luck to all ! -Mike-

Hey All,

The Regen has it's var cap and coil on the base board ,but I got side tracked by Summer and it won't be ready in time .So.....

Going with a two circuit Tuggle Xtal set w/ trap as needed. Ant unit not fully done but can be used, it is a Grail coupling cap, Grail ant tank cap w/ 660/48 Swiss cheese thin styrene cylinder.

Just wound the det coil today (660/48 on Swiss Cheese thin styrene cylinder).

She came out at a higher L than expected ,but according to the Deephaven resonance calculator,it SHOULD tune to the top end. I DO like my coils to tune a bit below the B'cast Band though.The signal generator should tell me where I wind up.

Still need to mount coil but should have it up and running by contest time.

Det V.C. will be 4 gang ceramic run wiperless. Diode FO 215 or Shottkies,phones misc SP or xtal ph w/ matching xformers/benny.

K

Yes, this summer is going by pretty fast. Was hoping to use my 6SK7 / 6J5 set, but it's not working as well as I'd like it to on some bands.

Pulled my "long - in - tooth" 6C8G set off the shelf last night and it's working as good as ever. Tuned in Radio Australia this morning like no one's business. Might just run that one again. Interestingly, I use the same plug in coils in both sets, so I know it's not a problem with the coil...

I'll fiddle with the pentode - triode set a bit more before giving up on it. Where it works good, it fills the headphones. Other times, it won't quite "grab" stations that the 6C8G set will with little trouble. For instance, was listening to Voice of Russia on the 6C8G set last night. Pentode/triode set wouldn't quite pick it up. Strange, but I guess that's what keeps us tinkering.

Rob

Hey Rob and All,

Tell me about tinkering! Initial tests on Kluge Tuggle are a mixed bag. Pretty good local selectivity and some moderate hand cap issues (an indication of "decent" Q ?).

Yet Dx signals tough to pull out (due to weak summer conditions?) .Outboard RF bias from signal generator is a BIG help,but is not really the way I wanted to go.

I think that the tank coil is also "looping in" locals some making it a bit harder to separate Dx.

FWIW tuning a bit short, she barely makes the 1600 local with a tiny bit left over. Little hope for X band as is.

So far a few New Yorkers,but nothing to really write home about. I listened to bit of the Yankees game on WCBS.

I think I need more heat. Maybe a quick MPF 102 conversion is in order.


K

Krystallo,

Well, if you can get your Kluge Tuggle to work in these conditions it's going to rock once things improve a little. Are you running the FO-215?

"Rob"

Count me in! I will be using my "Homemade R392"--RF stage with two 26fz6's into a 26d6 converter/osc. All circuits lifted from the R392 manual!
--except tuning is done with a variable cap-not variable inductors as in the REAL R392. IF strip is three 6he7's into a low distortion 'precision rectifier' detector/agc....into 8 watt amp.....antenna is center fed long wire 200 ft long up about 50 ft....
Radio is built in modular form....dont have it all together yet-no front panel. ect......but boy does it work!
-Hope the bands hold up.
Don in Nashville

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"Love is grand...divorce is about a hundred grand"

Hey Rob,

Yes. I was running the FO 215. I got a better "barefoot" (no RF bias) results late last night (WJR, New Yorkers up better,etc).

But I have still hand cap issues ( and I am short of shaft insulators right now).

Also the series ant coupling cap has TOO much effect on tuning.On previous sets this cap was more of a "peaking cap" that would goose a signal up 10 or so % ,but not drag the set around .As it stands THREE caps must be lined up just right and even WITH the sig gen as a "tuning aid", it can be a bit of a challenge.

Oh well, just fooling around and no big deal .


K

Maybe you could force a piece of clear pvc tubing, or fuel hose, on to the shaft and add a 1/4" extension rod.

Not the best but may be far better than nothing?

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