Date: Wed, 22 Dec 93 04:30:31 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 V93 #140 To: Ham-Homebrew Ham-Homebrew Digest Wed, 22 Dec 93 Volume 93 : Issue 140 Today's Topics: - - television disruptor - - (4 msgs) Mini-Circuits MAR-6 amp Ramsey 6m (5 msgs) Ramsey 6m/Micor/surplus Receiver questions ... 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: 21 Dec 93 11:44:09 GMT From: ogicse!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!pipex!barclay!usenet@network.ucsd.edu Subject: - - television disruptor - - To: ham-homebrew@ucsd.edu In article <5HFwec7w165w@spectrx.saigon.com>, dallas@spectrx.saigon.com (dallas) writes: |> quixote@eskimo.com (Looking for Sancho) writes: |> > I would be interested in obtaining some device which would |> > disrupt television reception around my apartment. If they |> > are not so complicated, I imagine that with some patience, |> > one could build one, but I do not even know the range of |> > frequencies used by commercial television radio waves. Why not ask him to turn it down? If he's not the sort of person who listens to reasonable requests, do you not have local noise-pollution laws? If so you caould report him for anti-social behaviour/being too loud. -- +---------------+-------------------------------------------------------------+ | Iain R Laskey | Atari Falcon - The best upgrade I ever made! | | | Laserdisc & Pro-Logic - The only way to watch movies | | | Replies to ilaskey@cix.compulink.co.uk | +---------------+-------------------------------------------------------------+ ------------------------------ Date: Wed, 22 Dec 1993 05:26:17 GMT From: kgw2!markm@uunet.uu.net Subject: - - television disruptor - - To: ham-homebrew@ucsd.edu In article quixote@eskimo.com (Looking for Sancho) writes: > The intended use of this device is to be put with a timer > against the wall where my new neighbor has his television set. If it's right up against the wall, you could get a really big magnet, like from a 12" woofer or bigger. You could make a large electromagnet too. Then, stand right at the closest point to his TV and move the magnet around a whole bunch. It should make his picture wave around enough to make him think he's sleepy or to just make him scratch his head. Fun to do to people's computer monitors too. And no FCC violation involved. - Mark Malson markm@xetron.com ------------------------------ Date: 20 Dec 93 06:36:50 GMT From: mvb.saic.com!connected.com!beauty!rwing!eskimo!quixote@network.ucsd.edu Subject: - - television disruptor - - To: ham-homebrew@ucsd.edu I would be interested in obtaining some device which would disrupt television reception around my apartment. If they are not so complicated, I imagine that with some patience, one could build one, but I do not even know the range of frequencies used by commercial television radio waves. The intended use of this device is to be put with a timer against the wall where my new neighbor has his television set. He comes home around midnight and keeps his television loud until 3 am almost every day. I wonder about the legality of my idea, therefore I would like something with regulated signal strength since I would not like to affect other neighbors. Any information about where one can buy these devices or where one can find a simple circuit to make one, (I know very little about radio or electronics), will be greatly appreciated. Thanks, Carlos. ------------------------------ Date: 20 Dec 1993 11:03:31 -0500 From: yeshua.marcam.com!zip.eecs.umich.edu!destroyer!news1.oakland.edu!w8hd!w8hd!not-for-mail@uunet.uu.net Subject: - - television disruptor - - To: ham-homebrew@ucsd.edu quixote@eskimo.com (Looking for Sancho) writes: > I would be interested in obtaining some device which would > disrupt television reception around my apartment. If they > are not so complicated, I imagine that with some patience, > one could build one, but I do not even know the range of > frequencies used by commercial television radio waves. > The intended use of this device is to be put with a timer > against the wall where my new neighbor has his television set. > He comes home around midnight and keeps his television > loud until 3 am almost every day. I wonder about the legality > of my idea, therefore I would like something with regulated > signal strength since I would not like to affect other neighbors. > Any information about where one can buy these devices or where > one can find a simple circuit to make one, (I know very little about > radio or electronics), will be greatly appreciated. The power of your device is of little concern; you would be, as the FCC would consider, maliciously interfering with a federally licensed facility. Although I empathcise with your position, you would be considered the bad guy here..... -- kenh@w8hd.org Ken Hoehn - Teletech, Inc. Compuserve: 70007,2374 N8NYO P.O.Box 924 FAX: (313) 562-8612 Dearborn, MI 48121 VOICE: (313) 562-6873 ------------------------------ Date: 21 Dec 93 12:08:33 GMT From: ogicse!cs.uoregon.edu!sgiblab!barrnet.net!nntp.crl.com!crl.crl.com!not-for-mail@network.ucsd.edu Subject: Mini-Circuits MAR-6 amp To: ham-homebrew@ucsd.edu J.D. Cronin (jdc3538@ultb.isc.rit.edu) wrote: : Have any of you folks tried the Mini-Circuits MAR-6 as a 2-meter (or : other ham band) preamp? It has 50 ohm input/outputs, and looks like : very few parts are needed. Are they any good? Is there anything : special to watch out for? Yep. Amps like these that are already matched for 50 ohms are actually somewhat undesirable for pre-amp use because unless you transform up to a higher impedance in your input circuitry before you transform back down, the pre-amp will be very broadband. Strong signals in the FM, AM, HF, you name it band could create real havoc for you. The only real selectivity you will have to protect you from intermod will be the antenna itself. Your situation will determine if you can use one of these. If you are not in an urban area -- maybe no problem. I would lean towards a FET device with a higher Q input matching network. 73's Don Miller KM4AS dmiller@crl.com ------------------------------ Date: 21 Dec 93 15:31:05 GMT From: ogicse!emory!kd4nc!ke4zv!gary@network.ucsd.edu Subject: Ramsey 6m To: ham-homebrew@ucsd.edu In article <009774D81F6FFD20.24E058BA@drager.com> landisj@drager.com (Joe Landis - Systems/Network Mgr. - x2621) writes: > >Where does one get these Micor radios? I've read several references to them >on the net. Never seen them at a hamfest. Also, are there hi band units >available? Are they convertable to 2M? You go to the wrong hamfests. :-) There are usually *stacks* of Motorola Micors and GE Mastr series radios at all the hamfests I attend. Low band units are often dirt cheap, but the high band and UHF rigs are starting to command premium prices. Also, newer Motorola surplus is now becoming more popular as the supply of Micors being taken out of service begin to run out. Gary -- Gary Coffman KE4ZV | I kill you, | gatech!wa4mei!ke4zv!gary Destructive Testing Systems | You kill me, | uunet!rsiatl!ke4zv!gary 534 Shannon Way | We're the Manson Family | emory!kd4nc!ke4zv!gary Lawrenceville, GA 30244 | -sorry Barney | ------------------------------ Date: 21 Dec 1993 04:47:26 GMT From: koriel!newscast.West.Sun.COM!abyss.West.Sun.COM!sunspot!myers@ames.arpa Subject: Ramsey 6m To: ham-homebrew@ucsd.edu In article 24E058BA@drager.com, landisj@drager.com (Joe Landis - Systems/Network Mgr. - x2621) writes: >myers@sunspot.West.Sun.COM (Dana Myers ) writes ... >>Subject:Re: Ramsey 6m >>Date: 17 Dec 1993 18:19:54 GMT >>Message-ID:<2est8aINN1ri@abyss.West.Sun.COM> > >stuff about Ramsey 6M kit deleted... > >>For the $200 price tag of the kit and cabinet, you could buy a >>VHF lo-band Micor with a 60W output level, and four channels >>worth of crystals and elements. You'd have a considerably >>superior radio, though it would be larger and use crystals. > >Where does one get these Micor radios? I've read several references to them >on the net. Never seen them at a hamfest. Also, are there hi band units >available? Are they convertable to 2M? OK.... I don't have time to answer this question in detail but I will take a short crack at it. In time, I promise, I will provide a FAQ on using commercial gear on amateur bands. You need to find out who deals in surplus two-way radio gear in your area. It really helps if you meet a local enthusiast that "knows the ropes". There are good units and there are bad units for amateur use; only gurus know how to identify which is which. It usually has to do with the ability to read part numbers stamped on the PC boards. Also, the type of radio you want will vary with respect to your application; some radios are phase modulated and good for voice and 1200 baud packet, while others are direct-FM and good for voice, 1200 baud and 9600 baud packet. Another place to look is a two-way radio shop. They often have mobiles for sale, but I've found the prices tend to be higher than a good surplus yard. There are people that advertise in rags like Nuts and Volts that have good stuff; I don't recall the name or number, but the gent that advertises every month in Nuts/Volts from Rialto, CA offers some good deals on complete mobile combinations. Last I spoke to him he had Lo-band high-split VHF mobiles which directly tune to 6m, 60W, for $75 including a pair of channel elements and a control head,etc. Yes, there are VHF Hi-band units around that tune directly to 2m. You really want the Hi-band Lo-split 138-150Mhz radios; "converting" these involves ordering the correct crystals, installing them in the channel elements, and following the tuning directions in the service manual. Oh! Don't be a cheapskate! Buy or borrow the service manual! *DO* follow the directions in the service manual. I've also found that 150-162Mhz radios will often work down to 146Mhz, but it is a crap shoot. I'm not an exalted guru, but I do have access to many Motorola and GE manuals, which makes me a guru, so I can answer questions about part numbers as time permits. Now... back to the GM300 I'm setting up on packet... :-) --- * Dana H. Myers KK6JQ, DoD 466 | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * This Extra supports the abolition of the 13 and 20 WPM tests * ------------------------------ Date: 20 Dec 1993 18:40:51 GMT From: koriel!newscast.West.Sun.COM!abyss.West.Sun.COM!sunspot!myers@ames.arpa Subject: Ramsey 6m To: ham-homebrew@ucsd.edu In article <519.784.uupcb@loebbs.com> john.lockridge@loebbs.com (John Lockridge) writes: >On 'Date: Sun, 19 Dec 1993 01:21:10 GMT' >In a message concerning 'Subject: Re: Ramsey 6m' >'rich@mulvey.com' wrote > >'Ramsey kits are generally considered to be bottom-of-the-barrel >quality, ...' > >The above comment leaves me with the following question which I >hope has a positive answer. Where can I find a kit or a series of kits >for good quality 6m equipment (receivers, transmitters, and/or >tranceivers)? Probably the most encouraging answer is that you can buy old Motorola and GE commercial radio gear quite inexpensively and get the manuals from the vendors and use these excellent radios as platforms for your own experimentation. If all you want is a radio to yak on 6m, you can order crystals or PROMs and tweak the radio up on 6m. Besides that, I know of no quality kits for 6m FM gear. Ramsey is cheese, pure and simple. -- * Dana H. Myers KK6JQ, DoD 466 | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * This Extra supports the abolition of the 13 and 20 WPM tests * ------------------------------ Date: 21 Dec 1993 20:43:38 GMT From: olivea!koriel!male.EBay.Sun.COM!newscast.West.Sun.COM!abyss.West.Sun.COM!sunspot!myers@uunet.uu.net Subject: Ramsey 6m To: ham-homebrew@ucsd.edu In article <1993Dec21.153105.9958@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >In article <009774D81F6FFD20.24E058BA@drager.com> landisj@drager.com (Joe Landis - Systems/Network Mgr. - x2621) writes: >> >>Where does one get these Micor radios? I've read several references to them >>on the net. Never seen them at a hamfest. Also, are there hi band units >>available? Are they convertable to 2M? > >You go to the wrong hamfests. :-) > >There are usually *stacks* of Motorola Micors and GE Mastr series radios >at all the hamfests I attend. Low band units are often dirt cheap, but >the high band and UHF rigs are starting to command premium prices. Also, >newer Motorola surplus is now becoming more popular as the supply of Micors >being taken out of service begin to run out. Keep in mind that most commercial radios come in more flavors than just "VHF Lo-band", "VHF Hi-band" and "UHF". Each band comes in "splits", for example, 138-150Mhz, 150-162Mhz and 162-174Mhz. Usually, the most critical difference between splits is the tuning range of the receiver front end filter, but the exciter and power amplifier modules also can be specified for splits. Exciters and power amplifiers often can be easily modified to change splits, but receiver filters are mechanical helical resonators, and are much harder to reliably change. At the same time, the 150-162 split will often tune (i.e. peak) on the 2m amateur band. Now that many agencies are converting to trunked radio, conventional VHF, UHF and 800/900 MHz mobiles are showing up more and more. Anything built in the 1980s is usually going to be synthesized with a PROM to select channels, more modern stuff is programmed with a computer. Don't let this stuff frighten you; I've seen people turn down a complete Syntor UHF mobile in cherry condition for $50 because it uses a PROM. Heck, the PROM can often be had for maybe $50 from an authorized Motorola dealer, you get sixteen or more channels. I have three MCX100 VHF high-band mobiles that I bought and got programmed for under $100; these particular models are excellent voice/packet rigs. Note: just like amateur radios, there are good synthesized commercial and less good synthesized commercial radios. For example, my MCX100s are "Fast-Lok", they lock up in 3mS, where the normal model takes 100mS to lock up. Neither radio, by the way, has the annoying 5kHz ring that most modern amateur radios do. > >Gary >-- >Gary Coffman KE4ZV | I kill you, | gatech!wa4mei!ke4zv!gary >Destructive Testing Systems | You kill me, | uunet!rsiatl!ke4zv!gary >534 Shannon Way | We're the Manson Family | emory!kd4nc!ke4zv!gary >Lawrenceville, GA 30244 | -sorry Barney | -- * Dana H. Myers KK6JQ, DoD 466 | Views expressed here are * * (310) 348-6043 | mine and do not necessarily * * Dana.Myers@West.Sun.Com | reflect those of my employer * * This Extra supports the abolition of the 13 and 20 WPM tests * ------------------------------ Date: 20 Dec 1993 19:30:03 GMT From: sgiblab!swrinde!cs.utexas.edu!howland.reston.ans.net!usenet.ins.cwru.edu!lerc.nasa.gov!news.larc.nasa.gov!grissom.larc.nasa.gov!kludge@ames.arpa Subject: Ramsey 6m To: ham-homebrew@ucsd.edu In article <2f4rjkINN33d@abyss.West.Sun.COM> myers@sunspot.West.Sun.COM (Dana Myers ) writes: >In article <519.784.uupcb@loebbs.com> john.lockridge@loebbs.com (John Lockridge) writes: >> >>The above comment leaves me with the following question which I >>hope has a positive answer. Where can I find a kit or a series of kits >>for good quality 6m equipment (receivers, transmitters, and/or >>tranceivers)? > >Probably the most encouraging answer is that you can buy old >Motorola and GE commercial radio gear quite inexpensively and >get the manuals from the vendors and use these excellent radios >as platforms for your own experimentation. If all you want is a >radio to yak on 6m, you can order crystals or PROMs and >tweak the radio up on 6m. Why bother? Fair Radio Sales has lots of nifty military surplus rigs that already cover the 6M band. Not high-powered gear in general, but pretty much plug-and-play. On the other hand, you can pick up a Motorola commercial mobile set for $50 around here, and some of the military rigs will cost three times that. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." ------------------------------ Date: Tue, 21 Dec 1993 20:33:13 GMT From: yuma!galen@purdue.edu Subject: Ramsey 6m/Micor/surplus To: ham-homebrew@ucsd.edu In article <1993Dec21.153105.9958@ke4zv.atl.ga.us> gary@ke4zv.atl.ga.us (Gary Coffman) writes: >In article <009774D81F6FFD20.24E058BA@drager.com> landisj@drager.com (Joe Landis - Systems/Network Mgr. - x2621) writes: >>Where does one get these Micor radios? I've read several references to them >You go to the wrong hamfests. :-) ********** Deletions ************ >newer Motorola surplus is now becoming more popular as the supply of Micors >being taken out of service begin to run out. >Gary I've read where the FCC is going to limit deviation to half of what it is now in the business bands. The article goes on to claim this will create a ' xx billion dollar economic stimulus' when everybody replaces their equipment, dumping tons of the used stuff on the surplus market. It sounds like it's just the VHF and UHF bands, so probably no 6m capable stuff. Food for thought, Galen, KF0YJ ------------------------------ Date: 14 Dec 93 20:11:41 GMT From: sdd.hp.com!col.hp.com!srgenprp!alanb@hplabs.hp.com Subject: Receiver questions ... To: ham-homebrew@ucsd.edu Victor Tavernini (tavernin@sun1.interlan.com) wrote: : I just recently purchased a Ten-Tec Century 21 and I noticed that the : receiver's sensitivity is rather poor (it's spec'd at 1uV) and I was : wondering ... : and it has no gain stage in from of the first mixer ... would a broadband : preamp increase performance significantly!? Would the proper place : to insert a preamp be between the T/R Switch and the Bandpass Filters? For most applications, 1 uV is all you need on the HF bands (assuming SSB-type IF bandwidth.) The only exceptions might be a very quiet location on 10 meters when the band is quiet or when using the HF receiver with a VHF/UHF converter that has inadequate IF gain. : How much gain and what type of noise figure should the preamp have? 1 uV sensitivity, assuming 10 dB S/N and 2 kHz bandwidth, implies a 24 dB noise figure. To get this down to 10 dB NF (.2 uV sensitivity), you could use a preamp with a 7 dB noise figure and 17 dB gain. AL N1AL ------------------------------ Date: Tue, 21 Dec 93 14:32:19 GMT From: mnemosyne.cs.du.edu!nyx10!lkollar@uunet.uu.net To: ham-homebrew@ucsd.edu References , <5HFwec7w165w@spectrx.saigon.com>, x1 Subject : Re: - - television disruptor - - I've seen electric motors, even battery-powered ones, do all sorts of interesting things to TV reception. Cheap ones that smell like ozone when they're running are best for this application. (Hint: lots of sparks.) ObHam: I clobber my own TV every time I key up the 2m rig, even at 1 watt power into a Ringo. I suspect I'm overloading the mast-mounted Rat Shack preamp, but putting an open stub (matched for 2m) on the preamp didn't seem to help.... It annoys my wife to no end, but she's the only one in the house that watches broadcast TV (I usually don't bother and the kids use the VCR to control their own programming). Reminding everyone not to contact me on 2m while "Doctor Quinn" is on, I am -- -- Larry Kollar, KC4WZK | I like CW, but that doesn't mean I think every ham lkollar@nyx.cs.du.edu | should have to learn it. "On the Internet, nobody knows you're a dog." ------------------------------ End of Ham-Homebrew Digest V93 #140 ****************************** ******************************