Date: Sat, 17 Sep 94 04:30:29 PDT From: Ham-Equip Mailing List and Newsgroup Errors-To: Ham-Equip-Errors@UCSD.Edu Reply-To: Ham-Equip@UCSD.Edu Precedence: Bulk Subject: Ham-Equip Digest V94 #332 To: Ham-Equip Ham-Equip Digest Sat, 17 Sep 94 Volume 94 : Issue 332 Today's Topics: (none) Helical Filters (was: Info needed on RF Concepts 2m/440 Amp) Info needed on RF Concepts 2m/440 Amp Kenwood TS-60S info please Micor Compa-station for 6m? Motorola MX 350 manual needed Need a DIAL knob replacem Needed: source for 25W capable marine VHF rubber ducky antenna RFI proof phones SPECTRUM ANALYZER Why can't DSP filters be put in low-level audio path? (2 msgs) WTB-Kenwood TM-631 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-Equip Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives/ham-equip". 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: 16 Sep 94 17:52:00 GMT From: news-mail-gateway@ucsd.edu Subject: (none) To: ham-equip@ucsd.edu UNSUBSCRIBE ------------------------------ Date: 16 Sep 1994 10:30:34 -0400 From: psinntp!JH.Org!not-for-mail@uunet.uu.net Subject: Helical Filters (was: Info needed on RF Concepts 2m/440 Amp) To: ham-equip@ucsd.edu paulc@fc.hp.com (Paul Christofanelli) writes: >Steve Steinberg (ss@JH.Org) wrote: >: o I read somewhere that due to intermod on HTs you shouldn't use >: preamps, is this true? >I'm not sure where you live, but unless it's pretty uncrowded, an FT530 >with a vertical rooftop antenna is going to suffer lots of intermod, >spurious response, etc. A preamp is only going to make it worse. >Bag the preamp on the amp and get a helical filter to use with the >rooftop antenna (or keep the preamp and still get a filter). Note >that the 530 is certainly no worse than either ICOM or Kenwood late >model dual-band HT's. Can anyone give me a source of 2m & 440 filter? Is there a combined 2m/440 unit, or would this defeat the purpose? How can I use 2 filters together for my dual-band HT? 73s, Steve waiting impatiently for his ticket, 7 weeks & 5 days . . . -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ss@jh.org Steve Steinberg Amateur Radio Callsign: _______ ------------------------------ Date: 16 Sep 1994 02:13:04 -0400 From: ihnp4.ucsd.edu!ucsnews!sol.ctr.columbia.edu!howland.reston.ans.net!swiss.ans.net!newstf01.cr1.aol.com!newsbf01.news.aol.com!not-for-mail@network.ucsd.edu Subject: Info needed on RF Concepts 2m/440 Amp To: ham-equip@ucsd.edu In article <355gk0$1hk@tadpole.fc.hp.com>, paulc@fc.hp.com (Paul Christofanelli) writes: : etc etc etc intermod problems are worsened with the preamp, so turn it off in an urban area. at least you have it available when out of the urban jungle. i use this amp in chicago and as long as i turn the preamp off in the downtown area it works fine. by the time i get 10 miles outside downtown i turn it back on and everything works fine. you can excite the amp with as little as 1 watt on uhf or vhf, at least i do with a kenwood th78-a. ------------------------------ Date: 16 Sep 94 09:34:05 PDT From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!europa.eng.gtefsd.com!library.ucla.edu!csulb.edu!nic-nac.CSU.net!clstcs!armyrman@network.ucsd.edu Subject: Kenwood TS-60S info please To: ham-equip@ucsd.edu In article , lopez@pktr.desy.de writes: > Does anyone on this group have any experience with the Kenwood TS-60S compact > 6 metre all-mode rig. What is the US price for this piece of kit? [ 2400 DM in > Germany is a little steep I think so I'm tkinking of importing direct from the > US] many thanks gerry [F35LOP.dsyibm.desy.de] DD5AX -- Hi Gerry, The TS60S here in the states is going for around $1200 US Not sure how many DM that converts to, but that's alot of money here. It's just about the same price as the TS50S! Is it just me?? Why is this radio so exspensive? Has anyone actually bought one of these? 1200 bucks for 6 meters seems rediculus --- Alex R. Myrman - KC6TMB - armyrman@clst1.sci.csupomona.edu College of Science Computational Systems - (909) 869-4226 California State Polytechnic University, Pomona, CA. USA ------------------------------ Date: 14 Sep 1994 14:46:03 -0700 From: news.sprintlink.net!news.world.net!news.teleport.com!news.teleport.com!not-for-mail@uunet.uu.net Subject: Micor Compa-station for 6m? To: ham-equip@ucsd.edu For Sale/Trade: Motorola "Micor Compa-Station", 100W 4-channel business band (47 MHz) base station, continuous duty rated, suitable for use as 6 Meter repeater. $150/offer/trade for 2M vertical or 2M mobile transceiver. <<503-655-6410>> 73's Gene KB7WIP ------------------------------ Date: Wed, 14 Sep 1994 16:53:43 GMT From: newshub.sdsu.edu!nic-nac.CSU.net!usc!howland.reston.ans.net!math.ohio-state.edu!magnus.acs.ohio-state.edu!csn!col.hp.com!news.dtc.hp.com!hplextra!hplntx!hpscit.sc.hp.com@ihnp4.ucsd.edu Subject: Motorola MX 350 manual needed To: ham-equip@ucsd.edu The unit has crystals, not a synth (unfortunately). It has a new battery and an almost new drop in charger. Was owned by the Idaho Fish & Game Department. If I can't get it tuned up/working, I'll likely have to sell it, in which case the battery and charger are likely worth much more than the non-receiving radio. I've not called Motorola parts (yet), as their manuals run in the $20 to $40 range. I was hoping to get a photocopy for the repair effort (as it would be cheaper) and then if the radio works, get a real manual. Thanks for your replies -Kevin The statements/opinions expressed here are not necessarily those of the Hewlett-Packard Company. HP paid a research firm millions of dollars to get their own opinions, and has made it clear they do not wish to share mine. Kevin C. Hess (KB7UKR) Hewlett-Packard Network Printer Division hess@hpdmd48.boi.hp.com (208) 396-3384 Boise, Idaho 83704 ------------------------------ Date: Wed, 14 Sep 94 09:30:00 -0800 From: news.claremont.edu!kaiwan.com!ledge!darryl.linkow@uunet.uu.net Subject: Need a DIAL knob replacem To: ham-equip@ucsd.edu SG>somewhere but now It's gone for good. I would glady buy it from anyone or SG>I'd appreciate if you could let me know where to get it. Just order from: Yaesu 17210 Edwards Road Cerritos, CA 90701 (310) 404-2700 Give them a call and ask for the parts department. If they can't help you, no one can! --- * OLX 2.2 * Darryl Linkow (818)346-5278 9 am - 5 pm PDT ------------------------------ Date: Wed, 14 Sep 1994 14:34:13 -0400 From: netcomsv!butch!rapnet.sanders.lockheed.com!skydvr.sanders.lockheed.com!user@decwrl.dec.com Subject: Needed: source for 25W capable marine VHF rubber ducky antenna To: ham-equip@ucsd.edu Hi all, I'm looking for a rubber ducky style antenna for a 25W marine VHF radio. Why would someone want such a thing, you ask? Well, on racing sailboats we do need a VHF, but we don't need the added weight of the antenna, or worse, the cable, up at the masthead. So we typically put a conventional metal marine 1/4 wave whip on the stern pulpit. Anyhow, the other day we saw a boat with a rubber 1/4 wave VHF antenna. We liked it because it looked safer and more robust than the metal whip. Unfortunately, I have been unable to locate a source for it. Any pointers to such a beast, or to public service or Ham antennas that could be tuned, would be greatly appreciated. Please email because I do not subscribe to this group. Thanks, Scott (straurig@mailgw.sanders.lockheed.com) ------------------------------ Date: 13 Sep 94 13:45:32 GMT From: news-mail-gateway@ucsd.edu Subject: RFI proof phones To: ham-equip@ucsd.edu 40 meter contesting and interfering with the answer phone is getting old, both for me and my wife. Its a GE, and I've tried all kinds of filtering. Anybody got any ideas for rfi proof answer phones? Reply to me, I'll summarize. Thanks. Fred KE7X ieefc@msu.oscs.montana.edu ------------------------------ Date: 14 Sep 1994 13:49:25 GMT From: ihnp4.ucsd.edu!ucsnews!newshub.sdsu.edu!nic-nac.CSU.net!usc!howland.reston.ans.net!vixen.cso.uiuc.edu!usenet.ucs.indiana.edu!master.cs.rose-hulman.edu!news@network.ucsd.edu Subject: SPECTRUM ANALYZER To: ham-equip@ucsd.edu Thanks to all who responded to our offer of the old HP spectrum analyzer. We have given it to a ham who is doing GHZ work on AMSAT,s , and will come and pick it up. Best of 73,s to everyone DAVE K9ZCE ------------------------------ Date: Thu, 15 Sep 1994 19:36:43 GMT From: psinntp!arrl.org!dnewkirk@uunet.uu.net Subject: Why can't DSP filters be put in low-level audio path? To: ham-equip@ucsd.edu David Feldman (dgf@netcom.com) wrote: : For all of the DSP filter products I'm aware of, they sit on the 8 ohm audio : output before the speaker. It seems this would expose the DSP to the rig's : AGC action, making it harder to recover a desired weak signal when a strong : (undesired) signal is nearby. : Do any of the DSP products have low-level connections appropriate for the : audio path before the AGC? In particular, I'd like to use a DSP with a : Ten-Tec Argonaut (which makes the pre-AGC audio available on a loop-thru : basis at the accessory connector). : Any comments or recommendations? The Ten-Tec Argonaut--and I assume you don't mean the Argonaut II--and some other Ten-Tec radios of several equipment generations back used audio AGC, but--at least in analog radios--non-RF-derived AGC is an anachronism in high-performance gear except in highly specialized applications. So looking for an audio DSP product to have I/O ports of levels and impedances suitable for use "before AGC" may vector your search into the weeds. You're onto something worthwhile, however, in the sense that letting the audio you want to low-level filter go all the way through your radio's audio chain and out through its power-amp IC so you have to attenuate it for application to the DSP circuitry is a hair on the dumb side -- *except* that these DSP boxes are aftermarket devices, and must default to "8 ohms in," input attenuation and containing their own seemingly redundant power amps because none of our radios have low- or line-level "send" and "receive" audio jacks (like sound-reinforcement and recording panels tend to have for 'FX'--sound effects--devices like reverbs, phasers, delay lines, etc) necessary to do it the "right" way. It would be best if we could patch audio DSP into our radios as soon after our radios' detectors as possible, assuming that matters of gain distribution and noise figure are under control. Warranty matters aside, if you're willing and able to dig into your radio and DSP box and do a bit of patching, you could probably effect the necessary low-level I/O yourself. (This is assuming that your radio's post-DSP audio chain would be worth using, by the way; even some multikilobuck radios have significantly hissy power-output chips that we might as well let aftermarket, "8-ohm input" DSP clean up.) Regards, David Newkirk, WJ1Z Senior Assistant Technical Editor *QST* ------------------------------ Date: 16 Sep 94 03:35:30 GMT From: news.delphi.com!BIX.com!hamilton@uunet.uu.net Subject: Why can't DSP filters be put in low-level audio path? To: ham-equip@ucsd.edu Following up on Dave Feldman's and Dave Newkirk's comments, I just don't understand what's so hard about having a pair of jacks on the back of the rig so you route the audio thru some outboard processors before it goes to the power amp stage. Are all the major manufacturers that dumb or just deaf that can't get this message? The stereo manufacturers (and come to think of it, aren't some also ham equipment manufacturers?) have had this figured out for 20 years. Can you component? I knew you could. Setting aside questions about whether it's more "efficient" or whatever to send the preamp vs. power amp outputs thru a DSP, it should be obvious they are not equivalently convenient! On my FT-990, e.g., there are some Din connectors for connecting a TNC. The audio output to the TNC is fixed-level, allowing me to turn the volume down independently once I've got a station tuned in. Great! But if I want to put a DSP in there, I've got to give that feature up. Why, for heavens' sake? Regards, Doug Hamilton KD1UJ hamilton@bix.com Ph 508-358-5715 FAX 508-358-1113 Hamilton Laboratories, 13 Old Farm Road, Wayland, MA 01778-3117, USA ------------------------------ Date: Fri, 16 Sep 1994 09:45:05 -0700 (PDT) From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!news.sprintlink.net!monopoly.callamer.com!usenet@network.ucsd.edu Subject: WTB-Kenwood TM-631 To: ham-equip@ucsd.edu I looking to buy a Kenwood TH-631 2 meter / 1-1/4 meter dual band radio. If you have one and are interested in selling it please call me (805-5443397) or E-mail me (smsmith@pinot.callamer.com) with your condition and price. Thanks! Steve Smith, KC6WRD ------------------------------ Date: 16 Sep 1994 10:03:43 -0700 From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!barrnet.net!nntp.crl.com!crl4.crl.com!not-for-mail@network.ucsd.edu To: ham-equip@ucsd.edu References , <1994Sep15.193643.5088@arrl.org>, om Subject : Re: Why can't DSP filters be put in low-level audio path? In article , hamilton@BIX.com (hamilton on BIX) wrote: > On my FT-990, e.g., there are > some Din connectors for connecting a TNC. The audio output to the TNC > is fixed-level, allowing me to turn the volume down independently once > I've got a station tuned in. Great! But if I want to put a DSP in > there, I've got to give that feature up. Why, for heavens' sake? Doug - In addition to the TNC audio, there is another fixed-level audio out on the back of your FT-990. Check the labels on the RCA jacks for "AF Out" (look at the bottom row of jacks). There is also a variable-level output ("SPEAKER Out") in the top row of jacks. Therefore, you can have your audio DSP -and- your packet too, since packet audio is on one of the DIN pins. Or, you may wish to run the (packet) audio throught the DSP unit before processing by the TNC. Lou ------------------------------------------------------------------------ Internet: lgenco@crl.com Lou.Genco@LChance.sat.tx.us Ham Radio Packet: N5SGL @ K3WGF.#SAT.TX.USA tcp/ip: n5sgl@sat.ampr.org ------------------------------------------------------------------------ ------------------------------ End of Ham-Equip Digest V94 #332 ******************************