Date: Sun, 30 Jan 94 04:30:27 PST From: Ham-Homebrew Mailing List and Newsgroup Errors-To: Ham-Homebrew-Errors@UCSD.Edu Reply-To: Ham-Homebrew@UCSD.Edu Precedence: Bulk Subject: Ham-Homebrew Digest V94 #14 To: Ham-Homebrew Ham-Homebrew Digest Sun, 30 Jan 94 Volume 94 : Issue 14 Today's Topics: Antenna Tuner Project Advice Needed Crazy VFO (2 msgs) HF circuit advice needed High Voltage Power Supply (2 msgs) Tuner modules (Have you seen any?) Using ICOM filters in SONY ICF-2010/2001D? XTAL source needed Send Replies or notes for publication to: Send subscription requests to: Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the Ham-Homebrew Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-homebrew". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: Fri, 28 Jan 1994 13:43:16 GMT From: ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!usenet.ins.cwru.edu!gatech!wa4mei.ping.com!ke4zv!gary@network.ucsd.edu Subject: Antenna Tuner Project Advice Needed To: ham-homebrew@ucsd.edu In article <2i8muq$k53@titan.wordperfect.com> mb@xmb (0000-Admin(0000)) writes: >Richard Measures, AG6K, wrote an article in the Feb. 1990 QST about a >balanced antenna tuner, made for just such an antenna system as you >describe. The balun is at the input of the tuner (i.e., between the >transmitter and the tuner). The tuner itself consists of two roller >inductors for the series reactances and a variable capacitor for the >shunt reactance. > > +----+ > | v L1 > +-((((((--+------- > | |/ >--- -+ ----- > balun ----- C1 --> to ladder line >--- -+ /| > | | > +-((((((--+------- > | ^ L2 > +---+ > >The roller inductors are mechanically ganged by a belt and pulleys on >the inductor shafts. The idea of a balanced tuner feeding a balanced >transmission line to a balanced antenna is appealing... Yes it is, but be careful of C1. It has to float hot and most variable capacitors have one side attached to the frame making it hard to maintain balance. You can mount it on a sheet of plexiglass, and don't forget an insulated tuning shaft. A capacitor that has both sets of plates insulated from the capacitor frame is best, but they're harder to find. Gary -- Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | we break it. | uunet!rsiatl!ke4zv!gary 534 Shannon Way | Guaranteed! | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | | ------------------------------ Date: 28 Jan 1994 08:13:01 GMT From: usc!howland.reston.ans.net!cs.utexas.edu!swrinde!sgiblab!sgigate.sgi.com!olivea!flash!robertov@network.ucsd.edu Subject: Crazy VFO To: ham-homebrew@ucsd.edu I cannot exlplain this to myself : I build a VFO that is very similar to the VFO of the "Optimized QRP Transceiver" from Roy W. Lewallen W7EL , the only difference is that it is not for the same frequency because I have to use it in a etherodyne transceiver born for fixed cristal oscillatorA operations. The Vfo was performing good , after warming up for 20 minutes it was moving in a range of max 20 Hz. The frequency from power-on increase of 90-100 Hz. The operating frequencies are from 8050 to 8190 more or less. Output 1.5 Volts pp over a 50 ohm load. Now the problem is that if I put the vfo inside its metal box to make it usable and connecting the box itself to the ground of the vfo (as it should be ) etc etc ... In a few words putting it in its final state then it starts to become instable increasing or decreasing its frequency of more than 800 or more Hz and trying to drift also after more than 1 hour from power-up. The last info I used a copper board like one for pcb scraching out copper for making the needed wiring leaving a lot of copper for the ground connections I hope to have done a good desriptions of the item. Also I took out from the box the VFO and it returned to original good performance. IT IS DRIVING ME CRAZY !!!!!! Roberto ------------------------------ Date: 28 Jan 1994 15:17:24 GMT From: news.cstar.andersen.com!news.acns.nwu.edu!casbah.acns.nwu.edu!rdewan@uunet.uu.net Subject: Crazy VFO To: ham-homebrew@ucsd.edu In article <2iahed$k2u@olivea.ATC.Olivetti.Com>, Roberto Valfredini wrote: > >I cannot exlplain this to myself : > >I build a VFO that is very similar to the VFO of the >"Optimized QRP Transceiver" from Roy W. Lewallen >W7EL , the only difference is that it >is not for the same frequency because I have to use it in a >etherodyne transceiver born for fixed cristal oscillatorA >operations. > >The Vfo was performing good , after warming up for 20 minutes >it was moving in a range of max 20 Hz. >The frequency from power-on increase of 90-100 Hz. > >The operating frequencies are from 8050 to 8190 more or less. >Output 1.5 Volts pp over a 50 ohm load. I built mine for the 20m band and it puts out about 2vpp into a 50 ohm load. (after the buffer). An unrelated comment: did you pick up the new buffer from the feedback column in Nov 1980 QST? >Now the problem is that if I put the vfo inside its metal box >to make it usable and connecting the box itself to the ground of the >vfo (as it should be ) etc etc ... >In a few words putting it in its >final state then it starts to become instable increasing or decreasing >its frequency of more than 800 or more Hz and trying to drift also after >more than 1 hour from power-up. > >The last info I used a copper board like one for pcb scraching out copper >for making the needed wiring leaving a lot of copper for the ground connections > >I hope to have done a good desriptions of the item. > >Also I took out from the box the VFO and it returned to original good >performance. > >IT IS DRIVING ME CRAZY !!!!!! It would drive me crazy too. ;( I think that there may be two things going on: 1. a long term problem such as heating that is contributing to drift after an hour and 2. a short term problem that may be related to improper grounding/ground loops or not stiff enough connection between vfo and box. This could lead to: - abrupt changes in parasitic capacitance and tuned frequency as components move about - not so micro micrphonics - parasitics induced because of inductance from ground loops and parasitic capacitance. This may also explain the increased long term drift as the components get warmer. Rajiv aa9ch r-dewan@nwu.edu ------------------------------ Date: 26 Jan 1994 21:35 EST From: vtserf.cc.vt.edu!solaris.cc.vt.edu!vtcc1.cc.vt.edu!sherrerdw@uunet.uu.net Subject: HF circuit advice needed To: ham-homebrew@ucsd.edu Hi, I need advice on building an induction heater of about 1 - 2 kW for outgassing electrodes and vacuum tubes. I was considering modifing a transmitter for this purpose. The frequency should be around 1 - 1 MHz. If someone already has something suitable I would be interested in a possible trade, purchace, etc. P.S. If you have an expensive power tube which needs repair I may be able to rebuild it for you. -thanks! David "SHERRERDW@VTCC1.CC.VT.EDU" or 717-993-3596 ------------------------------ Date: Thu, 27 Jan 1994 15:19:22 GMT From: spool.mu.edu!howland.reston.ans.net!EU.net!Germany.EU.net!netmbx.de!zrz.TU-Berlin.DE!zib-berlin.de!uni-paderborn.de!urmel.informatik.rwth-aachen.de!newsserver.rrzn.uni-hannover.de@sdd.hp.com Subject: High Voltage Power Supply To: ham-homebrew@ucsd.edu Hi OM`s I need a high voltage power supply for a tube PA. But I can`t find the right schematic and part list. The tube runs with a current of 7000V and 2Amp. I hope you can help me. Thank's Martin ------------------------------ Date: Thu, 27 Jan 1994 16:36:16 GMT From: sdd.hp.com!hpscit.sc.hp.com!cupnews0.cup.hp.com!jholly@network.ucsd.edu Subject: High Voltage Power Supply To: ham-homebrew@ucsd.edu Martin Stille (msti0087@rz.uni-hildesheim.de) wrote: : Hi OM`s : I need a high voltage power supply for a tube PA. : But I can`t find the right schematic and part list. : The tube runs with a current of 7000V and 2Amp. : I hope you can help me. : Thank's Martin hmmm, 7kv x 2 amp, about 14kw on the plate....thats one healthy afterburner. You should be worried about the coax feed also. ------------------------------ Date: 28 Jan 94 04:33:45 GMT From: usc!howland.reston.ans.net!agate!apple.com!amd!amdahl!JUTS!p1svp10!dws30@network.ucsd.edu Subject: Tuner modules (Have you seen any?) To: ham-homebrew@ucsd.edu I've been trying to get a hold of a few Mitsumi CATV 17, 18, or the new 19 tuner modules. If you have seen any of these laying around in fair supply please respond. Thanks.... -- -------------------------------------------------------------------------- Dave Sharpe Sunnyvale Ca. DWS30@duts.ccc.amdahl.com -------------------------------------------------------------------------- ------------------------------ Date: Thu, 27 Jan 1994 17:43:20 GMT From: nntp.ucsb.edu!library.ucla.edu!europa.eng.gtefsd.com!howland.reston.ans.net!newsserver.jvnc.net!raffles.technet.sg!ntuix!ntuvax.ntu.ac.sg!asirene@network.ucsd.edu Subject: Using ICOM filters in SONY ICF-2010/2001D? To: ham-homebrew@ucsd.edu Hi, Does anyone know if I can use the SSB filters for ICOM or for Kenwood in other radios or in my own IF strip? I am thinking of use for SSB/RTTY/CW. The reason I ask is because the Kiwa filters I want are not available locally but the ICOM filters are. Does anyone who have access to both know? I am looking to put the ICOM narrow filters (2.4 kHz) into my SONY ICF-2010/2001D. Does anyone have any comments about doing this? 73 de 9V Daniel ------------------------------ Date: 27 Jan 1994 17:06:49 GMT From: sdd.hp.com!hpscit.sc.hp.com!rkarlqu@network.ucsd.edu Subject: XTAL source needed To: ham-homebrew@ucsd.edu >In article patrick_tatro@stortek.com (Patrick Tatro) writes: >>Im looking for a vendor willing to supply crystals in the 1 or 2 quantity >>basis. Most vendors have minimum quantities that far exceed my needs. I am >>also not sure if I can locate crystals at 16.660Mhz and 16.600Mhz. Im trying >>to convert an FM pocket tranciever into a cordless phone unit. Any help will >>be greatly appreciated. Also, Hy-Q Intl. in Erlanger, Kentucky. They don't mind selling small quantities and can give 2 day delivery if necessary. Rick Karlquist rkarlqu@scd.hp.com ------------------------------ Date: 27 Jan 1994 15:49:08 GMT From: sdd.hp.com!vixen.cso.uiuc.edu!howland.reston.ans.net!sol.ctr.columbia.edu!news.columbia.edu!namaste.cc.columbia.edu!mac20@network.ucsd.edu To: ham-homebrew@ucsd.edu References , <654f02la5b3Z01@JUTS.ccc.amdahl.com>, <2i6sje$987@b11.b11.ingr.com>edu Subject : Re: IBM-PC Shareware for PCB Photo work I've pretty much settled on CIRCAD from Holophase in Fl. (thanks Al) I did not find it on an FTP site but first found it on Online America which had a very old version. I called Holophase up and then later downloaded it directly from their very small, but 14,400 BBS. They offer a very attractive discount to Hams also for the full registered version. The demo i have is limited in number of parts etc.. but quite functional. Mike Cecere Applied Physics Department Columbia Univeristy ------------------------------ Date: Thu, 27 Jan 1994 17:36:26 GMT From: sdd.hp.com!cs.utexas.edu!howland.reston.ans.net!newsserver.jvnc.net!raffles.technet.sg!ntuix!ntuvax.ntu.ac.sg!asirene@network.ucsd.edu To: ham-homebrew@ucsd.edu References <1994Jan25.191202.1@ntuvax.ntu.ac.sg>, <1994Jan26.001852.3038@ke4zv.atl.ga.us>, <2i68cr$isj@reznor.larc.nasa.gov>tuvax.n Subject : Re: Antenna pre-amp design. Help! In article <2i68cr$isj@reznor.larc.nasa.gov>, kludge@grissom.larc.nasa.gov (Scott Dorsey) writes: > In article <1994Jan26.001852.3038@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >> >>In looking through my collection of ARRL Handbooks, I don't find a >>HF preamp until I go back to the 1962 edition. They have one using >>a 6AK5 pentode. This should give you an idea of the apparent lack >>of need for such circuits with more modern equipment. > Gary is probably right but then if you look in the MFJ catalog I am sure you will find one or two active antennas, which are quite expensive when you consider the number of components involved. Thus in case of the lack of a good antenna, active antennas/pre-amps still help. > Actually, I recommend this circuit... I built it when I was a kid and > hung it on the front of a modified Philco table radio and it worked very > nicely to the point where the rotten selectivity of the radio was a problem. > The manufacturer probably never expected anyone to tear windings off the > AM loopstick to move it to 80M. > --scott However, a valved pre-amp was not quite what I had in mind :) I was thinking more along the lines of the dual-gated mosfets or bi-polar types for broadband amplification as well as for narrow band. :) > -- > "C'est un Nagra. C'est suisse, et tres, tres precis." 73 de 9V Daniel ------------------------------ Date: 26 Jan 1994 22:58:54 GMT From: news.ingr.com!b11!cmack.b11.ingr.com!dlkerl@uunet.uu.net To: ham-homebrew@ucsd.edu References <16fT02SH5bd501@JUTS.ccc.amdahl.com>, , <654f02la5b3Z01@JUTS.ccc.amdahl.com>1.ingr Subject : Re: IBM-PC Shareware for PCB Photo work (From a posting in sci.electronics from Christopher Webster (cxw14@psuvm.psu.edu) Tue, 1 Jun 1993 20:33:12 EDT) > Several freeware schematic/PCB CAD programs are available via anonymous ftp > from rigel.acs.oakland.edu (141.210.10.117). These are contained in the > "pub/msdos/cad" directory; read "00-index.txt" first to see what's > offered. I've used this S/W also; it is excellent. The documentation leaves something to be desired; nowhere is it stated that you can mirror text (strings) by selecting text for moving, then typing an 'x'. Small complaint for something that's free; I've used it for several boards already. -Dan Kerl dlkerl@cmack.b11.ingr.com ------------------------------ End of Ham-Homebrew Digest V94 #14 ******************************