From savage@artofnoise Mon Sep 28 14:54:35 1992 Received: from artofnoise.rtp.dg.com by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA08334; Mon, 28 Sep 1992 14:54:35 -0400 Received: by artofnoise (5.4.2/rtp-s04) id AA00696; Mon, 28 Sep 1992 14:54:20 -0400 From: savage@dg-rtp.dg.com (Ed Savage) Message-Id: <9209281854.AA00696@artofnoise> Subject: Just a test (please ignore)... To: fm-10@dg-rtp.rtp.dg.com Date: Mon, 28 Sep 92 14:54:19 EDT X-Face: tl]OjXK9`O/*24)Mlc!A%Sg11f&06Gf%("s.nCj[B<0*4?{9Gj@6n"U$5F;,Lx8i*O#'tt7 rjqZ7D4>Xu3YWTe'G&'gGc:>;(~vzw3t0st85h|e{w0&qkm$ oYQUsJppl";p4cI%-@-niG]!N^;=NLps{g7G_1*pDZj3uHC*C*A(2Uce%k1IAN4#h3Ua_CFDQWn*V6 |4-+!AEBjB+0+>50LbOlhI?wY05`d9lx7N$h/"i#B4t0Lv`hyyzh?~H^S To: fm-10@dg-rtp.dg.com Subject: 38 kHz xtal I got one of those Epson 38 kHz crystals from DigiKey and it doesn't work with my FM-10. I hooked it up through a 10 pF cap like it shows on the BA1404 data sheet but I could get no stereo pilot lighting on my receiver. At least with the variable capacitor I could get the stereo light to flicker once in a while! So it could be that this crystal does not meet the requirements of the BA1404. I post this as a caveat to others who are thinking of getting this crystal. If anybody has used it and gotten it to work please let me know. The BA1404 data sheet suggests a Kyocera KF-38E or STATEK equivalent. ========================= scotbri@rosemount.com Scott Brigham (AA0HU) St. Paul, MN USA ========================= From fkuhl@maestro.mitre.org Tue Sep 29 15:57:47 1992 Received: from mwunix.mitre.org by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA07173; Tue, 29 Sep 1992 15:57:47 -0400 Return-Path: Received: from maestro.mitre.org by mwunix.mitre.org (5.61/SMI-2.2) id AA18075; Tue, 29 Sep 92 15:53:58 -0400 Received: from snare.mitre.org by maestro.mitre.org (4.1/SMI-4.1) id AA16624; Tue, 29 Sep 92 15:56:05 EDT Date: Tue, 29 Sep 92 15:56:05 EDT From: fkuhl@maestro.mitre.org (F. S. Kuhl) Message-Id: <9209291956.AA16624@maestro.mitre.org> To: fm-10@dg-rtp.dg.com, scotbri@rosevax.rosemount.com Subject: Re: 38 kHz xtal >From: scotbri@rosevax.rosemount.com (Scott Brigham) >To: fm-10@dg-rtp.dg.com >Subject: 38 kHz xtal > >I got one of those Epson 38 kHz crystals from DigiKey and it >doesn't work with my FM-10. I hooked it up through a 10 pF >cap like it shows on the BA1404 data sheet but I could get > > I got fine results with exactly that part and 2 22-pf caps in series to replace the 10 pf cap as shown on the data sheet. Frederick Kuhl fkuhl@mitre.org Center for Advanced Aviation System Development The MITRE Corporation From lloyd%eastern@uunet.uu.net Mon Oct 12 01:53:00 1992 Received: from RUTGERS.EDU by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA19447; Mon, 12 Oct 1992 01:53:00 -0400 Received: from mimsy.UUCP by rutgers.edu (5.59/SMI4.0/RU1.4/3.08) with UUCP id AA00489; Mon, 12 Oct 92 01:17:57 EDT Received: by mimsy.UMD.EDU (smail2.5) id AA01579; 12 Oct 92 01:17:36 EDT (Mon) Received: from mail.uunet.ca (via uunet.ca) by relay1.UU.NET with SMTP (5.61/UUNET-internet-primary) id AA14942; Mon, 12 Oct 92 01:11:41 -0400 Received: from eastern by mail.uunet.ca with UUCP id <10321>; Mon, 12 Oct 1992 01:11:32 -0400 Received: by eastern.eastern.COM (/\==/\ Smail3.1.24.1 #24.11) id ; Sun, 11 Oct 92 22:30 EDT To: fm-10@dg-rtp.dg.com From: lloyd@eastern.com (lloyd) Message-Id: Date: Sun, 11 Oct 1992 22:30:38 -0400 Organization: Eastern's Public Access BBS, Toronto CAN Please remove my name from the mailing list. Thank you. lloyd@eastern.com From netronix!netronix.com!mycal@uunet.UU.NET Wed Oct 14 03:07:23 1992 Received: from relay2.UU.NET by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA12923; Wed, 14 Oct 1992 03:07:23 -0400 Received: from uunet.uu.net (via LOCALHOST.UU.NET) by relay2.UU.NET with SMTP (5.61/UUNET-internet-primary) id AA21269; Wed, 14 Oct 92 03:07:21 -0400 Received: from netronix.UUCP by uunet.uu.net with UUCP/RMAIL (queueing-rmail) id 030607.7493; Wed, 14 Oct 1992 03:06:07 EDT Received: by netronix.com (UUPC/extended 1.11q); Tue, 13 Oct 1992 09:41:39 PDT Date: Tue, 13 Oct 1992 09:41:38 PDT From: "Mycal Johnson" Message-Id: <2adafc44.netronix@netronix.com> Organization: Netronix, Inc. To: fm-10@dg-rtp.dg.com Subject: new faq file, archive... -- California Ballot Recommendations -- by your pal mycal@netronix.com ----------------------------------------------------------------------------- Prop. 155- NO Prop. 156- NO Prop. 157- NO Prop. 158- NO Prop. 159- NO Prop. 160- YES Prop. 161- YES Prop. 163- YES Prop. 164- YES Prop. 165- YES Prop. 166- NO Prop. 167- NO Cut Government Spending, Cut Government Control, Cut Govenment period. From wlsmith@valve.heart.rri.uwo.ca Wed Oct 14 15:17:43 1992 Received: from alex.ctrg.rri.uwo.ca by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA26454; Wed, 14 Oct 1992 15:17:43 -0400 Message-Id: <9210141907.AA00814@valve.heart.rri.uwo.ca> Date: Wed, 14 Oct 92 15:07:51 -0400 From: "Wayne Smith" To: fm-10@dg-rtp.dg.com Subject: Re: new faq file, archive... Huh? Your posting had no message body, just a subject and .sig. From bill@tv.tv.tek.com Thu Oct 15 13:21:49 1992 Received: from relay.tek.com by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA01941; Thu, 15 Oct 1992 13:21:49 -0400 Received: by relay.tek.com id ; Thu, 15 Oct 92 10:16:21 -0700 Received: from soul.tv.tek.com by tektronix.TEK.COM (4.1/8.0) id AA26635; Thu, 15 Oct 92 10:20:26 PDT Received: from thd.tv.tek.com by soul.tv.tek.com with SMTP id AA20546 (5.65c.tv/IDA-1.4.4 for ); Thu, 15 Oct 1992 10:15:23 -0700 Received: by thd.tv.tek.com (4.1/SMI-4.1(tv.tek.com)) id AA24202; Thu, 15 Oct 92 10:15:21 PDT Message-Id: <9210151715.AA24202@thd.tv.tek.com> To: fm-10@tv.tv.tek.com Subject: Where can I buy it? Date: Thu, 15 Oct 92 10:15:20 -0700 From: Bill McFadden I tried to order an FM-10 fit from "The Radio Collection" but was told they were having trouble getting the kits and would refund my money. Should I order directly from Ramsey? What are their prices? Thanks. -- Bill McFadden Tektronix, Inc. P.O. Box 500 MS 58-639 Beaverton, OR 97077 bill@tv.tv.tek.com, ...!tektronix!tv.tv.tek.com!bill Phone: (503) 627-6920 From netronix!netronix.com!mycal@uunet.UU.NET Thu Oct 15 14:35:56 1992 Received: from relay1.UU.NET by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA13133; Thu, 15 Oct 1992 14:35:56 -0400 Received: from uunet.uu.net (via LOCALHOST.UU.NET) by relay1.UU.NET with SMTP (5.61/UUNET-internet-primary) id AA20391; Wed, 14 Oct 92 23:35:32 -0400 Received: from netronix.UUCP by uunet.uu.net with UUCP/RMAIL (queueing-rmail) id 233147.16996; Wed, 14 Oct 1992 23:31:47 EDT Received: by netronix.com (UUPC/extended 1.11q); Wed, 14 Oct 1992 09:28:54 PDT Date: Wed, 14 Oct 1992 09:28:50 PDT From: "Mycal Johnson" Message-Id: <2adc4ac6.netronix@netronix.com> Organization: Netronix, Inc. To: fm-10@dg-rtp.dg.com Subject: fm10-faq (blush) sorry about that guys, for some reson the wrong file got attached to my mail. Here is what it should of been : Ok here is the new Ramsey FM-10 file. Please check out the info about the FM-10 archives. There is now a place we can store postscript or gif schematics, layouts etc. Also this mailing list will be archived there. Once again we have Ed Savage and the guys at Data General, NC for making yet another giant contribution. --------------------- cut ------------------------------------------------ Ramsey FM-10 Info by mycal@netronix.com 4th Edition ----------- Here is a rough compilation of information about the Ramsey FM-10, and BA1404 Stereo FM broadcasters. It is in no way complete, nor do I take any responsibility for its accuracy. I know you haven't seen this statement but a 1000 times but here it is : For informational purposes only. I have been swamped with requests for information about amps, antennas and other mods for the FM-10, so I decided to dig through my mailbox and notes and compile this file. I hope It helps, and if anyone has more information about the FM-10 or FM transmitters, please send it to mycal@netronix.com -or- gallaghe@sonoma.vax.edu. I will try to update this file as new information arrives or is found out. A Postscript version with schematics and board layouts is also not out of the question. I would like to acknowledge the following people for the contributions and support: John Brewer -- brewer@anarky.enet.dec.com Alan Bryant -- uunet!csn.org!adb Greg Thornwall If I missed anyone, sorry, please drop me a note and remind me. FM-10 Mailing List ------------------ First Things First. There is now a mailing list that deals with the topic of the Ramsey FM-10 and other BA1404 based FM Stereo Transmitters. Feel free to join up and contribute. To send a message to the mailing list, send your question, reply, comment, or contribution to : fm-10@dg-rtp.dg.com To add or delete yourself from the list, send a short message with the function (add/delete/change address) along with the relevant e-mail address to: fm-10-request@dg-rtp.dg.com If you have any questions I can be reached at myca@netronix.com. Once again I want to thank Ed Savage and the guys at Data General, NC for making this list possible. FM-10 Archives -------------- Yes it is finally here, message archives of the fm10 mailing list and a place to put/find schematics, reviews, stories, etc. related to the FM-10 and other BA1404 based FM transmitters. People can FTP into dg-rtp.dg.com with user "anonymous" and password "". In the fm10 directory you'll currently find two sub-directories: incoming This is writeable by everyone and this is where people should upload new stuff. msg-archives This directory will have files named according to the date they were last "sealed". The file "Current" is a running log of all EMail messages from the last "seal" date of the archives. Other Places to Look -------------------- alt.radio.pirate is another good forum to find or post information on these kits. Although you may not have pirate aspirations, many of the things talked about can benefit everyone. other places to scan, sci.electronics and the amateur radio groups. Recommended Test Equipment -------------------------- An SWR/Power meter is a giant help, a CB to 2 meter one will suffice. Power readings will not be accurate, but can be useful for peaking. The most important part is the SWR meter, this is very important when making an antenna. Ramsey's Address ---------------- If your looking to purchase a FM-10 kit and can't find one locally try : Ramsey Electronics, Inc. 793 Canning Parkway Victor, New York 14564 Phone (716) 924-4560 Fax (716) 924-4555 Ramsey FM-10 70mw output amplifier ---------------------------------- Provides almost 9db gain to bring the output power of the Ramsey FM-10 Stereo transmitter from 8mw to 70mw. Not the best design, but all parts can be found at Radio Shack! +12v | / \ R1 *220 ohms(1/2 watt) / \ R2 9k | C2 -/\/\/\/-----------||-----> output | / | / | | / C1 | |/ <----------mps2222a (276-2009) in --||------|\ -or- 2n4401 ^ | -> -- | | | gnd currently on board * you can also use 2 440 ohm 1/4 watt resistors run in parallel I built this thing right on the underside of the FM-10 kit, C1 is the cap that currently goes to the RCA ant jack, the 9k and the 220 ohm resistor have to be bought, note that if you cannot find 220 ohms you can make one by using 2 440 ohm resistors in parallel, and that a 10k will work in place of the 9k but yealds poorer performance (-5%). Note that you can lower the resistance of the 220 ohm resistor to about 200 ohms for more power, but do not do this unless you can check to see if the transistor has gone into oscillation. The mps2222a is from Radio Shack part number 276-2009, use this part! if you substitute it for a 2n2222a you will get only half the gain. Be very careful to get the leads in the correct orientation! I have found that a 2n4401 can be used in place of the mps2222a with a little better performance, about 5mw more. I think the 2n4401 can be found at Radio Shack too. C2 is of the same value of C1, I took the one that goes to the on board antenna pad. Important! the value for R2 that seems to be optimal is 205 ohms, but it is very close to the sat point, If the amp. seems noisy (interferes with the TV etc.) back this value off to 220 ohms. If you lower this value below 200 ohms the power meter may read higher power but this will not be true, the transistor will be spewing all kinds of junk and the power meter will mistake this for higher output (in reality the signal we want will drop considerably.) Well that's it, effective range with a good antenna should be a little over double. ------- On Wed, 1 Jul 1992 13:16:47 -0600, "Alan D. Bryant" wrote: > The second stage idea didn't appear to do anything here, but I don't have any > measuring equipment, so it may have been a small enough improvement that I > couldn't detect it. > Hmm, very interesting, I haven't tested it in the real world, just with a HP power meter and spectrum analyzer. Also note that using a 2n2222a I could only get 30mw, but when using the mps2222a I got 75mw. This was all into a 50 ohm load, with a mismatched antenna it could actually degrade performance. I was kind of amazed when I calculated the optimal Rl and found it to be 52 ohms for that circuit. > I've been playing around with antennas a little myself. Made up a weird > concoction I'll have to describe to you at some point. No real test results > from it yet. I would like to hear about the details of what you have come up with when you get it all up and running. The $19 RS CB power meter would probable come in handy for doing antenna and power tests, It would be a lot better than nothing. ANTENNAS -------- Also Do you have a good antenna? I think that is the most important thing that you can do for extended range. I built a 1/4 wave ground plane using a UHF connector and 5 lengths of copper plated brazing rod (found at the local welding shop). Works great and only cost $3 dollars to make. use the formulas out of your FM-10 manual 234/freq=length of rod. insert the 4 ground plane rods in the 4 holes of the UHF connector, stick them through about 1/4 inch and solder. Solder the radiator in the top of the UHF connector (you may have to grind it a bit to fit.) Then bend the ground plane rods to a 45 degree angle to the radiator. There you have it a very effective antenna, just connect with a 50 ohm cb cable to your amplified ramsey, stick the antenna in a tree or in another high place and you should have 1 miles of solid coverage (when using the above amp.). Also If you have an SWR meter you can cut the rods a little longer and start clipping the ends off a little until you get the best SWR reading. | | | | = brazing rod | | | | | ----- ----- ----- = UHF connector | - | / - \ - | | / \ | | / \ The final antenna should look like this: | | // \\ That is 1 radiator pointing strait up and 4 ground plane radials. Be careful when you bend the brazing rod, don't break the connector. Grab the rod right below the connector with a pair of vice-grips (or the likes) and bend the brazing rod at that point. I have been told that you can shorten the radiator and make the ground radials longer to lower your radiation angle, but I haven't tried this, nor do I know what this would do to the antenna impedance. On The Road ----------- Old magnet mount CB antennas can make great mobile antennas, just take all of the base load out of them and cut the radiator to 1/4 wave length. If you need a longer radiator than the one that comes with the antenna use the above mentioned brazing rod. I've tried this antenna and it works great! It rivals my di-pole at home and you can drive to a high, optimal location for your broadcasts. You could also try a 5/8 wave length antenna, this would give you 2+db gain, or almost 2x power gain on transmit. Filter design for FM Radio Transmitters. ---------------------------------------- It is very important to have a clean signal, the way 99% of all people who get busted for illegal transmitting is that the people that live around them complain about interference. Do not do this, keep everyone happy, including yourself, be clean. When you amplify a signal, you get unwanted byproducts these are called harmonics. The show up at multiples of your starting frequency. For example if you amplify a 50mhz signal you may get echo's on 100mhz, 150mhz 200mhz, 250mhz... If you walk on your neighbors TV, the local fire depart- ment, or anyone else, you are going to get nailed. If you are only on the FM Band, you will hardly be noticed. .. I have looked into the filter design more, I have come up with these two: (basically scaled from the charts in the ARRL handbook). Filter Design: 7 element Chebyshev I run @ 88.1 so my 1st harmonic is 176.2 This filter seems ideal. Fc 3db 20db 40db 85.8mhz 95.9mhz 116mhz 148mhz .132uh .152uh .132uh -----()()()-----()()()-----()()()----- | | | | <-50ohm - 33pf - 68pf - 68pf - 33pf 50ohm-> - - - - | | | | -------------------------------------- | --- - Filter Design: 5 element Chebyshev Not as good as above, but thrown in anyway. Fc 3db 20db 40db 81.8mhz 105mhz 147mhz 222mhz .128uh .128uh -----()()()-----()()()----- | | | <-50ohm - 30pf - 62pf - 30pf 50ohm-> - - - | | | --------------------------- | --- - The tuff part in the above is winding the coils. 3t of #12 wire 1/2" diam should be about .12 uh. 4t is .17 uh. (but ugh, #12 wire is big stuff). I may just make all the coils 3t, and bend them around a little while watching the analyzer. Maybe use var-caps too. Well I will build this weekend and try Tuesday. I will let you know how it goes. mycal Very simple filter. ------------------- .15uH from fm10 >------()()()------> to antenna | | - c1 - c2 - - | | --- --- - - 88mhz 102mhz 107mhz c1 62pf 54pf 50pf c2 62pf 54pf 50pf its basically a scaled down version of the other filters. it won't knock the harmonics down as much as the other two designs but the good thing about this one is that it uses standard off the shelf parts. the inductor is one of those molded jobbies that looks like a resistor so you can make this very small. use the above cap values depending on which freq range you want to operate at. ie. if you run 87-90 use the 88mhz vals, 90-103 use 102mhz vals, and above that use 107mhz vals. use fixed value parts! ... I built the 7 element Chebyshev, I substituted .12 uh inducters for the .132 and .15 uh for the .152. Also I put 10-50pf var caps in place of the 33pf's and 10-90pf varcaps for the 68pf's. After a bit of tweeking I got -45db on the 2nd harmonic -55db on the 3rd -65 on the 4th, every thing else was off the scale. That is much better than -25db,-27db,-30db,-40db... -40db off the fundamental is required by FCC. [Actually the fcc says no more than .7mw out on any harmonic when dealing with VHF equipment, that's on top of the -40db requirement. But if you are running 1 watt out -40db is .1mw] I have found that peeking (buy tuning the var-caps) for maximum power output into a 50ohm load will give you close to maximum attenuation on the harmonics. Also the Fc can be raised or lowered quite a bit, I tried +-10Mhz (of 88Mhz) and could tune the Fc there. I am going to stick with the .12uh and .15uh inductors because I can get them for $.25 apiece at HSC, But I may try winding my own later on, especially if I use it on a high power output device. These molded inductors don't look like they can handle much power, but I have run 2 watts through them without problem.. On a side note, I don't think the Q of these inductors is that high, I think that if you wound the above mentioned #12 coils you would have a higher Q, hence, greater performance on the filter. On a second try I built another filter using variable inductor cans, and used fixed caps, this one seemed to have better performance than the last one, it was also much more stable. Var. caps are not very stable, so I would recommend using fixed caps. [Also of intrust is that the FM-10 puts out about 8-9mw and the 2nd harmonic is -25db off. The FM-4 Kit by ramsey puts out 130mw and the 2nd harmonic is only -12db off, which means the 2nd harmonic of the FM-4 is about as powerful as the FM-10.] FM-10 Myths ----------- 1) The fm-10 puts out 100mw of power. This is not true, or at least not true for the Ramsey FM-10's that I have tested. They put out between 8 and 15mw when driven with a 12volt supply. 2) The fm-10's output can be cranked up by reducing the value of R9. This like the above is not true. R9 and R10 are optimized for maximum output and greatest harmonic suppression at 12volts. There are much better ways of getting more output power than to mess with this output stage. FM-10 Improvements - -------------------- (Some from ACE magazine.) Stereo Pilot Mod ---------------- One of the first problems experienced with the FM-10 is difficulty in getting the stereo pilot to operate correctly. One solution is to replace C7 and C8 with a 38khz crystal, this works the best and is recommended. If you cannot find a 38khz crystal, you can make your life a whole lot easier with a couple part changes. As indicated on the Ramsey schematic, about 110pf is necessary to tune the oscillator. The components supplied to achieve this are a small fixed value capacitor (C7) abd a slightly larger value trimmer (C8). Since proper setting of the trimmer occurs within a very small 'window' (about 5% of the trimmers range), it can bet difficult or impossible to adjust the pilot to 19khz and have it stay put. This can be cured by increasing the value of c7 to 100pf and replacing c8 with a 6-50pf trimmer (Radio Shack #272-1340); a 5-30pf trimmer will do the trick. The RS trimmer will not fit the holes in the pc board; one needs to cut the leads off a spare resistor and solder them to the legs of the trimmer (just use bits of wire) to mount it on the component side of the board. Crystal Mod ----------- old set up new setup c8 c1 xtl where c1=10pf and xtl=38khz |-||-| |-||-|\|-| | c7 | | | v8=var cap |-||-| | | c7=cap | | | | Remove C7 and C8, replace with 38khz crystal and 10pf cap. Note that the 10pf cap and the crystal are running series and the old cap setup is running in parallel. Note: there have been good and bad reports on using the Epson crystal from digi-key. From what I have heard the crystal is quite delicate, and in at least one case the experimenter destroyed the crystal. In one of the positive case c1's 10pf cap was replaced by 2 22pf caps run in parallel, this yealded a rock solid stereo. Treble Boost Mod ---------------- Treble boost (pre-emphasis) improvement. The FM-10 appears to have been designed by someone outside the United States since it operates at the European audio standard of 50 microseconds. Receivers in the US are set up for 75 microsecond de-emphasis. R3 and R6 determine the time constant for the pre-emphasis curve. Replacing them with 75K ohm resistors (standard value 68K ohm is close enough) will result in improved audio response. A much better pre-empasis/input circut is shown in the July 1992 issue of "Radio Electronics". Not only do they use 75K ohm resisters in there pre-empasis, but they filter stray RF signals by inserting a .001 cap between pin 1 (of the BA1404) and ground, and pin 18 and ground. It has been noted that the above mod may actually cause distortion on cheaper stereo receivers, since they were mass produced for the world market, they were designed for the European audio standard, which Japan and other Asian nations use too. Try it out, let me know what works for you. Anti-Drift Mod -------------- There has been quite a bit of discussion on the FM-10's frequency stability. Complaints that digital receivers cannot lock onto the FM-10's signal for any great length of time. I have used the below mod with good results (I used an N750 negative temperature compensated disc), but I have been told that Mylar or Polystyrene caps are even better. The FM-10 was designed to be inexpensive and cost-saving measures with components are inevitable. Disc ceramic capacitors are less expensive than silver-mica caps, and also much less stable. Simply replace c16 with a silver-mica, tantalum or negative temperature compensated disc (say anywhere from N150 to N750) cap of the same value. ============== ============== ============== Other Raw Info ============== ============== ============== the 2sc2570 is supposedly replaceable with an ecg10. Also I have used an MRF901 for a replacement, but it yealds 2.5mw less output. The MRF239 can be used aas direct replacement for the Ramsey 2 meter PA kit. Cost is around $14 bucks. From: Greg Thornwall Mycal, I called the company that produces the BA-1404 chip. The company is the Rohm Corp. in TN. They sent me some interesting data on the chip: some electrical characteristic curves, list of distributors & representatives, application diagram and some similar block diagrams that comes with the FM-10. If you want any more info just write or call them up and they will send it free! Their address & number is: Rohm Corporation Rohm Electronics Division 3034 Owen DR Jackson Business Park Antioch, TN 37013 PH: (615)-641-2020 (ask for someone who deals with the BA-1404) FAX: (615)-641-2022 Also they have: PO Box 1399 Antioch, TN 37011-1399 --Greg (KD3SU) 38Khz Crystals.... > > Does anybody have any idea where to find 38KHz crystal (H-18). > > Don't know what a H-18 is, but you can use a C-2 type quartz crystal > for 38.000KHz by Epson America, Epson part number C-2 38.000KA-P, which can > be ordered, for example from Digi-Key Corporation (1-800-DIGI-KEY), Digi-Key > part No. is SE3314 Thanks Andrew, I've got the DK catalog H-18 is a solder welded case and C-2 is a cylinder type. I don't know if there is any difference in specs between them. Aaron B. .. From: Greg Thornwall I have some more stuff on another company that sells "pirate" electrical kits. Panaxis productions, PO Box 130, Paradise, CA 95967-0130 (916)-534-0417 ($1.00 for a catalog). They have a bunch of FM & AM transmitters from 20mW to 10W! They only sell PLANS for the high power transmitters here to the US and will sell kits for export elsewhere. They have a PLL FM oscillator (500mW) for sale in kit form for $129.00 (better stability!). From: uunet!toad.horizon.com!kevin (Kevin Criqui) Sorry for the delay - been super busy at work. The address I have for Panaxis Productions is PO Box 130, Paradise, CA 95967-0130. The phone number is (916)534-0417. My catalog has a $1.00 price printed on it, but I think they're $2 these days (still a bargain). I'm going to send my 2 bucks and get a new copy and see what fun stuff has been added. My little station consists of the "MMC1" Macromod Compander set for 2:1 compression, connected to the "SG" high performance stereo generator connected to the "FME" PLL FM exciter. Besides the Panaxis stuff, I have a homebuilt mixer console and of course, the 1 transistor PA. Prices from my catalog (which is likely to be out of date) are: Code Plans PCB P+P full kit ---- ----- --- --- -------- MMC1 12.00 18.00 26.50 87.00 SG 15.00 13.50 26.50 105.00 FME 17.50 15.00 24.50 129.50 While looking for my Panaxis catalog, I ran across a catalog from Communication Concepts, Inc. that has kits based on some of the AP Notes in the back of the Motorola RF devices data book (another must-have). They have a couple of 300 watt (!) kits that cover the 10-150MHz range (AR305 and AR313). There's another article (AN1037) that's a 300W amp specifically for 88-108MHZ FM broadcast use (but CCI didn't have it in their catalog back when I got my copy). CCI is at (513)426-8600 or (513)220-9677. .. From: gdavis@griffin.uvm.edu (Gary Davis) Many responded that they want to know more about the Oregon Comm Sys line of stereo PLL Fm transmitters. Here is their address and phone number: OREGON COM SYSTEMS 1257 Siskiyou Blvd Suite 132 Ashland,Oregon 97520 TELE: 503-271-3294 Models are stereo, 100mw output,PLL frequency syntehsis. Some come with audio mixers also. All are wired and tested. This would appear an ideal unit for driving a linear amp. Harmonic output is not specified,however low pass filter designs are not difficult. They also stock antennas. The FM units are rated with an audio response of 10 to 15 kilohertz +/- 2 db. Frequency coverage: 88-108 mhz RF output 100 milliwatts Frequency Stability +/- 100 hertz Response (audio) 10 hertz to 15 kilohertz +/- 2db Input level: 500mv cost: $109.00 Delux stereo models 149.95 ------------------ ------------------ Well I have more info, but it is not organized enough even for this rough sheet. Given time I will polish it an post it. Once more If you have any info, I stress "ANY", about this subject please drop me a byte or two. have fun, mycal@netronix.com -- From zycad!zycad.com!vijay@netcom.com Thu Oct 15 15:47:48 1992 Received: from netcomsv.netcom.com by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA25326; Thu, 15 Oct 1992 15:47:48 -0400 Received: from zycad.UUCP by netcomsv.netcom.com with UUCP (4.1/SMI-4.1) id AA24973; Thu, 15 Oct 92 12:47:01 PDT Received: from yoda.zycad.com by zycad (4.1/SMI-4.1) id AA12647; Thu, 15 Oct 92 12:35:33 PDT Received: by yoda.zycad.com (4.1/SMI-4.1) id AA14584; Thu, 15 Oct 92 12:36:35 PDT Date: Thu, 15 Oct 92 12:36:35 PDT From: vijay@zycad.com (Vijay Vaidyanathan) Message-Id: <9210151936.AA14584@yoda.zycad.com> To: fm-10@dg-rtp.dg.com Subject: Is anyone there using it for a "real" broadcast? I was interested in knowing whether there are folks out there using the FM-10 for a small scale broadcasting station? How do I go about getting an FCC license for a small area (say my neighbourhood?) ... I think it would be a terrific idea to get the school kids in the area to get involved with a venture like this ... Also a fine way to discuss neighbourhood issues ... I guess you'd put a crystal in place of the tuned LC oscillator for starters ... -VV ==== vijay@zycad.com ---- From edsi!gmeiers@cserver.plexus.com Fri Oct 16 06:14:33 1992 Received: from spool.mu.edu by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA16622; Fri, 16 Oct 1992 06:14:33 -0400 Received: from spool.mu.edu by spool.mu.edu (4.1/SMI-4.1) id AA00745; Fri, 16 Oct 92 05:14:31 CDT Received: by cserver.plexus.com (/\==/\ Smail3.1.25.1 #25.6) Thu, 15 Oct 92 17:25 CDT Received: by edsi.plexus.COM (/\==/\ Smail3.1.25.1 #25.3) id m0mfaZk-0001U0C; Thu, 15 Oct 92 14:09 CDT Message-Id: Subject: please add me to mailing list To: fm-10@dg-rtp.dg.com Date: Thu, 15 Oct 92 14:09:35 CDT From: Garrett Meiers X-Mailer: ELM [version 2.3 PL11] Hi. Could you please add me to your mailing list. Thanks alot. -- Garrett Meiers gmeiers@edsi.plexus.com From gil@Limbic.SSDL.COM Thu Oct 22 09:23:06 1992 Received: from UUCP-GW.CC.UH.EDU by dg-rtp.dg.com (5.4.1/dg-rtp-proto) id AA26063; Thu, 22 Oct 1992 09:23:06 -0400 Received: by UUCP-GW.CC.UH.EDU with UUCP id AA01249 (5.67a/IDA-1.5 for fm-10@dg-rtp.dg.com); Thu, 22 Oct 1992 08:22:52 -0500 Received: from limbic.UUCP by limbic.ssdl.com with UUCP id AA15692 (5.65c/IDA-1.4.4 for fm-10@dg-rtp.dg.com); Thu, 22 Oct 1992 06:51:45 -0500 From: "Gil Kloepfer Jr." Message-Id: <199210221151.AA15692@limbic.ssdl.com> Subject: Greetings from 99.7 MHz! To: fm-10@dg-rtp.dg.com Date: Tue, 20 Oct 92 22:35:41 CDT X-Mailer: ELM [version 2.3 PL11] Sender: gil@limbic.ssdl.com Hello everyone! My thanx to Mycal Johnson for his FAQ (forwarded to me by a friend) which led me to the mailing list. I got my FM-10 a couple of months ago, but haven't really done anything REAL exciting with it. I whipped-up a homebrew mixing board and went on-the-air in my apartment complex. My antenna is a poorly thought-out string of wire. I can say with reasonable certainty that the only one listening to my broadcasts was me. My kit came with R12 missing, but being an electronics hacker of sorts I had a 47K resistor around. My first problem after building the kit was that there was no stereo separation, even with the stereo light blazing away. I found that a better value for R12 was a 10K resistor. I now have almost no problem getting reasonable stereo separation with little distortion. The second problem I experienced was that the frequency drifted significantly depending on what object was near the PC board at the time. I ultimately mounted the board in an alumimum box and have a TV-style coax connector for the antenna connection. Tonight, I added the MPS2222A PA and the treble boost mod. The treble boost has the added effect of reducing the overmodulation that the FM-10 is known for. My PA bled quite a bit into TV channel 11 with the 220 ohm resistor, and so I changed that resistor to a 330 ohm (probably greatly reducing output) until I can make the filter mentioned in the FAQ. I also found that a small-value electrolytic placed in parallel with the power traces on the PC board near the RF amplifier connections help to limit the amount of hash that creeps into the audio circuitry. Unfortunately I'm better equipped to deal with digital circuitry than I am with RF. In fact, I'm almost dangerous around RF :). I look forward to the insight provided by others to keep me from visiting with the FCC. As soon as I get a reasonable antenna and have reduced any interference as much as possible, I'm going to leak out some info about the station and see if anyone in the apartment complex hears it. I'm looking forward to hearing your war stories! Gil.