Subject: glowbugs V1 #233
glowbugs          Thursday, January 29 1998          Volume 01 : Number 233

Date: Wed, 28 Jan 1998 06:23:24 -0700 (MST) From: Jack Meadows <jackmead@getnet.com> Subject: Re: Xtal Oscillator tubes/circuits... The place to be with your xtal oscillator is 3.579 Mhz evenings! Activity is increasing, with a great bunch of Boatanchor fellows. You will meet John, Sandy, Dennis, Bob, Mike, Paul and others. You will hear hartleys (small and huge), xtal osc, Valiants, Elmac's, ART-13's, homebrew everythings, all kinds of other commercial BA's and sometimes a surprise. I'm using my 813 xtal oscillator as well. Have a QRO amplifier ready, if the qrn is bad. Don't miss the great 80 meter band conditions right now! Hope to see ya there. Best regards, Jack W7QQQ
Date: Wed, 28 Jan 1998 09:24:43 -0500 (EST) From: "Robert D. Keys" <rdkeys@seedlab1.cropsci.ncsu.edu> Subject: Re: possible source of tubes > Hi! I'm Michael Miller - I'm new to the wonderful world of Ham Radio - busy > getting ready to take my first set of tests. I saw your posting to the CX > reflector. Welcome aboard. > Last week I was in Williamsport, Pennsylvania on business. Williamsport is > the home of Little League - where the LL World Series is held. It is 90 > miles north of Harrisburg, Pennsylvania's capital. > > After my business was done, I was exhausted, and walked through the small > downtown area. I walked into a small book/antique store - Do Fischer's > Books & Antiques. Very, very nice couple, just taking over from their > parents; I particularly liked how eager they were to help me look for things. > > I picked up some radio magazines from the 30s and a book on radio theory > from the 30s. What I am really looking for are books from the very early > 1900s on radio theory - just out of curiosity! They are around, but most of what I access are in my university's library. > The store owner of the store told me he bought an estate's holdings that > included, if I understood him correctly, a 1000 or so tubes. At present, > they are unsorted, but I think he would sort them if there were interested > parties. > > I'm a physician (I live north of Chicago - just joined the North Shore Radio > Club), and I have absolutely no fiscal interest in whether they sell their > tubes. I got to talking with these people, and felt a bit sorry for them - > I could tell their business was not doing all that well. Also, it was > obvious he had no idea what to do with all these tubes! So --- > > is this anything you or anyone in your listserv group would be interested > in? How are such potential business sources of tubes handled in your group? > If you are interested, let me know, and I will be glad to give you their > name and address. I will bounce this to the glowbugs email list and see if anyone in that area might be interested. > Thanks for hearing me out! Not yet to the boatanchor stage, but I may well > get there! Sounds like you are on your way! > Michael > Michael L. Miller, MD > millermd@nwu.edu Bob Keys/NA4G
Date: Wed, 28 Jan 1998 22:00:29 -0800 (PST) From: Ken Gordon <keng@uidaho.edu> Subject: HW-16 and chirp... FINALLY got it figured out and fixed! Thanks to the article in QST from 1950 on crystal oscillators. Found that adding a 220 pfd cap from screen to ground pretty much eliminated the chirp, even on 15 meters. Full 50 watts output on 15 even. Changed the osc. grid leak to 100 k. Have to adjust values a bit now, but heading in the right direction. Think 100k may be a bit too high for it and 220 pfd is too much, but that was what was called for in the above mentioned article for the 6AG7. NO CHIRP ANY MORE!!!! Also, discovered that whereas the schematic shows a .02 mfd cap as a keying "shaper" there was a .005 installed instead. Keying doesn't sound so hard now either. And, one reason I haven't been on the 3579 QRG much (in addition to the fact that I am gunging out the basement and making a REAL shack) is that one of the pins on the audio output tube BROKE OFF right at the glass/metal seal. Never have seen that before in a small tube. Hope to hear some of the 813 oscillators txs on soon. Ken W7EKB k
Date: Thu, 29 Jan 1998 00:39:20 -0800 (PST) From: talljazz@teleport.com (Dan Presley) Subject: Re: possible source of tubes A great book on the early theories of radio is "The How and Why of Radio Apparatus" by H.W.Secore.E.E. I picked this up as a reprint by Lindsay Publications. Adress PO Box 12, Bradley, Il 60915-0012. I believe they have done other vintage books as well. This was originally published in 1922, and does a nice job of explaining 'early radio'-spark & tube stuff. I got it at a local technical bookstore. Dan N7CQR
Date: Thu, 29 Jan 1998 09:04:54 -0800 (PST) From: Ken Gordon <keng@uidaho.edu> Subject: HW-16: Eliminating Chirp w/xtal control... 1) Change OSCILLATOR grid leak from 47 kOhm to 100kOhm 2) Connect a 100 pfd silvered mica or other high quality RF capacitor from oscillator screen grid to ground. 3) If you really want to go hog-wild, feed the screen grid through a good 1 to 2.5 mH RF choke, by-passed at the "cold" end with a .001 - .005 mfd cap, from a 150 volt regulated supply. Results: No chirp, even on 15 meters. Ken W7EKB
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