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tubeguy@myshop.com: Jan 07 01:33PM -0600 Is it possible to use a Signal Generator for an "In Home" radio transmitter?   I would like to make a small in the house AM radio transmitter, so I can listen to my own music collection of MP3 music on my antique radios. I know I can buy a transmitter for this use, but I am wondering if I can use what I already have.   For example, I have an Eico 315 Signal Generator. It has an internal 400cps audio generator, but it also has the capability of inserting another audio signal.   So, can I just take a MP3 player and run that into the signal generator, and connect the sig gen to a piece of long wire strung inside my home to transmit the signal? Is there enough power to transmit inside my own home? I'd probably string 10 to 20 ft of wire along the edge of the ceiling, or across curtain rods from window to window.   Of course I'd set the sig gen to an MW AM radio frequency, such as 16,500 kc.

Fox's Mercantile <jdangus@att.net>: Jan 07 02:55PM -0600 > Is it possible to use a Signal Generator for an "In Home" radio > transmitter?   Yeah, but it'll sound like crap. Because most of those old generators will only do about 30% modulation. And they're not exactly set up for any kind of modulation bandwidth.   There's the SSTRAN 3000 which I use. <http://www.sstran.com/> Another option is the Talking House transmitter. <https://www.ebay.com/itm/223314565635>   Or, you can roll your own. <https://antiqueradio.org/transmitter.htm>   -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

"pfjw@aol.com" <peterwieck33@gmail.com>: Jan 07 12:56PM -0800 > Is it possible to use a Signal Generator for an "In Home" radio > transmitter?   It is absolutely possible. And, the quality of the signal transmitted will be based on the quality of the generator. BUT:   Make sure your radiated power does not exceed FCC part 15 limits. Which, as I remember, is about 100 mw on the commercial AM band. Also, make sure you do not exceed antenna 'developed length' - which is very roughly ten (10) feet. You will get better results if you trim your antenna to the target frequency. When I lived and worked in Saudi, I covered 80 acres with an SSTRAN transmitter, using a based-loaded coil mounted about 10 meters above grade, and transmitting on 1380 AM. Not so good on the stucco-on-mesh villas, so I converted to FM in short order, using a Ramsey FM100B (1-watt). That covered a radius of about 5 km in good stereo.   Look up the FCC Part 15 rules for Medium Band AM.   Peter Wieck Melrose Park, PA

jurb6006@gmail.com: Jan 07 12:57PM -0800 You're off by a factor of ten. You want up to 1,650 KHz. Actually it is so easy to build an oscillator like that and easy to amplitude modulate that might be a better option. Well unless you have nothing better to do with the generator.   Crystal controlled would be better because drift is not good. But then if you just leave it on all the time it will settle in and be stable enough.   Another thing is to keep the power down, you don't need problems with the FCC. They got a SWAT team, I shit you not. I am not sure what you can get away with, maybe 100mW or 500, something like that. A quick Google didn't yield a straight answer but I would say just make sure the signal doesn't leave the house.   I know it is absolutely illegal to use any of the FM band, that this when they come and treat you like you're running a meth lab. However there is so much noise on AM that they might never even suspect. You might be better running the "transmitting antenna" through wires to the desired locations. I fit leaves the house, even on your own property that might mean trouble. And we are talking feds here, that means your miracle worker lawyer is no good.

Pat <forums@greensdomain.com>: Jan 07 04:00PM -0500 >ceiling, or across curtain rods from window to window.   >Of course I'd set the sig gen to an MW AM radio frequency, such as >16,500 kc.   Yes. Your signal generator can be used for that. I doubt you need more than a foot or two of wire for the antenna. The frequency you mentioned, however, isn't MW. It's short wave (which may possibly be received on your antique radios in addition to MW). Perhaps it was just a typo on your part, but the AM broadcast band is from 540 to 1700 kHz (formerly referred to as kc). 1600 to 1700 wasn't part of the band until after any radio called antique was sold, so 540 to 1600 is what you want to use.   Have Fun, Pat

Fox's Mercantile <jdangus@att.net>: Jan 07 03:06PM -0600 > Not so good on the stucco-on-mesh villas, so I converted > to FM in short order, using a Ramsey FM100B (1-watt).   Which is all well and good, but old table AM radios don't do FM.     -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Pat <forums@greensdomain.com>: Jan 07 04:13PM -0500 On Mon, 7 Jan 2019 12:56:59 -0800 (PST), "pfjw@aol.com"   >Look up the FCC Part 15 rules for Medium Band AM.   >Peter Wieck >Melrose Park, PA   I'm not sure what you meant by "trim your antanna to the target frequency". If you are talking about an antenna that is resonant at AM broadcast band frequencies, that is not practical (or legal as you correctly pointed out) for a home transmitter. One wavelength at 1600 kHz is 187 meters (over 600 feet).

Look165 <look165@numericable.fr>: Jan 07 10:36PM +0100 Think of PowerLine.

Jeff Liebermann <jeffl@cruzio.com>: Jan 07 02:31PM -0800 On Mon, 7 Jan 2019 15:06:24 -0600, Fox's Mercantile <jdangus@att.net> wrote:   >> Not so good on the stucco-on-mesh villas, so I converted >> to FM in short order, using a Ramsey FM100B (1-watt).   >Which is all well and good, but old table AM radios don't do FM.   No problem:   "Cuthbert FM to AM Converter MKII" <https://radiojayallen.com/cuthbert-fm-to-am-converter-mkii/>   This solves the problem for those who can't find anything worth listening to on AM, but want to listen on an antique radio. So, they listen to FM broadcast on the AM radio.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Mike <ham789@netscape.net>: Jan 07 02:53PM -0800 > ceiling, or across curtain rods from window to window.   > Of course I'd set the sig gen to an MW AM radio frequency, such as > 16,500 kc.   Short answer: NO. Longer answer: Check the FCC regulations for what you're allowed to do on what frequencies. Depending on where you live, you might get in trouble if some harmonic landed on some emergency frequency.   Turn on the generator; tune the radio to that frequency;Is the unmodulated signal absolutely quiet on your radio? Let it sit for an hour; is the generator still on the same frequency as the radio? If you got this far, you might have a chance.

whit3rd <whit3rd@gmail.com>: Jan 07 04:12PM -0800 > transmitter?   > I would like to make a small in the house AM radio transmitter, so I can > listen to my own music collection of MP3 music on my antique radios.   Well, yes, it's possible. But, it isn't necessary. There are Bluetooth options if your 'antique' radios can accept a bit of straightforward audio input. A variety of MP3-compatible Bluetooth players (like, maybe in your cellphone?) can be found, with Bluetooth output, and receivers are a common item: some inductive coupling to the audio signal channel could be easy to arrange.   If you can put an induction coil in the vicinity of the radios, it doesn't take much power to tickle an AM radio, with minimal AM interference at longer distances.

whit3rd <whit3rd@gmail.com>: Jan 07 04:24PM -0800 > Is it possible to use a Signal Generator for an "In Home" radio > transmitter?   This app note comes to mind: <https://www.analog.com/media/en/technical-documentation/application-notes/an47fa.pdf>   note especially figure 116

Roger Blake <rogblake@iname.invalid>: Jan 08 04:57AM > Or, you can roll your own. ><https://antiqueradio.org/transmitter.htm>   Very cool! I actually have a tube AM transmitter that I built from a Lafayette kit in 1970. Found a photo and description online:   http://boatanchorpix.x10host.com/LA23.htm   The design seems typically dangerous for the time, it's a wonder I managed not to electrocute myself or blow up other equipment with this thing! It would be interesting to try resurrecting it with some appropriate safety modifications.   -- ----------------------------------------------------------------------------- Roger Blake (Posts from Google Groups killfiled due to excess spam.)   NSA sedition and treason -- http://www.DeathToNSAthugs.com Don't talk to cops! -- http://www.DontTalkToCops.com Badges don't grant extra rights -- http://www.CopBlock.org -----------------------------------------------------------------------------

Jeff Liebermann <jeffl@cruzio.com>: Jan 07 11:00PM -0800 >Is it possible to use a Signal Generator for an "In Home" radio >transmitter?   All things are possible if you have enough time and money to throw at the problem.   >listen to my own music collection of MP3 music on my antique radios. I >know I can buy a transmitter for this use, but I am wondering if I can >use what I already have.   In college, we threw together a radio station based on an AM carrier current broadcast system. The key to the system was the isolation transformer between the transmitter output and the AC power line. You don't want 60 Hz going backwards into the transmitter causing hummmm and you do want the frequency response of the transformer to include the AM broadcast band. That's not easy as there are a bunch of compromises that need to be made. Our first transformer literally exploded when plugged in. Our 2nd version did a little better by only catching fire. When we tried to measure the RF impedance of the power line at 900KHz, we blew up the signal bridge.   We eventually bought a commercial system after the fire marshal decided that he would not tolerate an untested system. I got lucky and found an original data sheet: <http://www.steampoweredradio.com/pdf/lpb/lpb%202-20%20am%20carrier%20current%20system.pdf> Note the T-8 power line interface. On Page 6 it lists "Univ. State Poly, College" (Cal Poly Pomona) which is where we built the system.   A tube type LPB carrier current transmitter: <https://blogs.telosalliance.com/found-in-the-attic-february-2014>   >For example, I have an Eico 315 Signal Generator. It has an internal >400cps audio generator, but it also has the capability of inserting >another audio signal.   Doesn't have enough RF power for carrier current. It can probably be heard somewhat all over the house, but will probably be noisy.   >ceiling, or across curtain rods from window to window.   >Of course I'd set the sig gen to an MW AM radio frequency, such as >16,500 kc.   Try 1650 KHz instead. Kilocycles died 50 years ago.   I wrongly assumed that you wanted to do it down the power lines using a carrier current system. Yes, an inside antenna MIGHT work. I'm fairly sure that your signal generator doesn't belch enough RF power to be heard around the house without background noise. I suppose it would easy enough for you to try with your existing generator.   -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

"pfjw@aol.com" <peterwieck33@gmail.com>: Jan 08 06:04AM -0800 On Monday, January 7, 2019 at 4:13:43 PM UTC-5, Pat wrote:   > AM broadcast band frequencies, that is not practical (or legal as you > correctly pointed out) for a home transmitter. One wavelength at 1600 > kHz is 187 meters (over 600 feet).     http://www.sstran.com/pages/sstran_buildant.html   Go to the section on "tuning".   Peter Wieck Melrose Park, PA

"pfjw@aol.com" <peterwieck33@gmail.com>: Jan 08 06:12AM -0800 > I know it is absolutely illegal to use any of the FM band, that this when they come and treat you like you're running a meth lab. However there is so much noise on AM that they might never even suspect. You might be better running the "transmitting antenna" through wires to the desired locations. I fit leaves the house, even on your own property that might mean trouble. And we are talking feds here, that means your miracle worker lawyer is no good.   No. There are multiple FM & FM stereo Part-15 compliant transmitters. Typically, they are around 25 MW or so, and with a good antenna mounted high enough will easily cover a few acres.   https://sourcefmtransmitter.com/wp-content/uploads/2017/07/ramsey-fm100b-large.jpg   I keep this one, and it gets its heaviest use at Kutztown twice per year, covering both pavilions, and then some. Matched to this antenna:   http://img0016.psstatic.com/152423604_amazoncom-tru-match-fm-broadcast-antenna-kit---25-watts-.jpg   There are (at least) half-a-dozen more options.   Eventually, I am would like to set up a small NTSC TV transmitter, as TVs are becoming a greater and greater presence at Kutztown. But, it is something I would never use at home.   Peter Wieck Melrose Park, PA

John-Del <ohger1s@gmail.com>: Jan 08 06:38AM -0800 > Eventually, I am would like to set up a small NTSC TV transmitter, as TVs are becoming a greater and greater presence at Kutztown. But, it is something I would never use at home.   > Peter Wieck > Melrose Park, PA   Years ago, I used to feed my shop's cable box into a distribution amp to cover the several drops I had around my store, one of which I fed into an antenna. This would allow quick verification of TVs with just putting my finger on the antenna terminal of any TV. One day the cable co. shows up and said we had a huge leak and wanted to check for an open ground. I switched off the AB switch feeding the antenna and the problem was gone.   In any case, you can try feeding the RF output of any VCR or any RF modulator into a decent VHF amp and feed an antenna. Probably cover the area you need without spending any money.

tubeguy@myshop.com: Jan 07 01:33PM -0600 Over the years I have acquired a lot of vintage test equipment. I still use most of it, but I have the following, which I think is something I will never use. I only work on Tube gear, or real early transistor stuff without chips. That means I will never work on any flat screen modern HDTV televisions.   There are three devices:   1. Flyback tester. I KNOW that is obsolete, modern TVs dont have flybacks, only CRTs use them.   2. Sweep generator and marker. This one I am not sure about????   3. Bar Generator. (Puts colored bars both horizontal and vertical on the screen). [This one I guess is still useful.]   I also have one of those High Voltage Probes for my Eico VTVM. That I know is obsolete and is only for CRT sets.   Anyhow, I'm thinking of selling some of this stuff. I like collecting and restoring old tube radios, stereos, and audio and guitar amplifiers, but I dont have room for old tube television sets, even though it would be nice having one of those antiques. But I dont really plan to do anymore work on televisions. My own TVs and computer monitors are all flat screen types now, and if they die, I will simply replace them, unless its a simple repair such as a blown fuse, bad power switch or a broken wire.   --- The reason that most of the old wax capacitors have failed, is because the bees wax was gotten from "Low Tech" bees!

tabbypurr@gmail.com: Jan 08 04:17AM -0800 > 2. Sweep generator and marker. This one I am not sure about????   > 3. Bar Generator. (Puts colored bars both horizontal and vertical on the > screen). [This one I guess is still useful.]   I don't see how that would be useful. A computer can put anything at all onto a video signal, not stuck to a few preset testcard images.   > I also have one of those High Voltage Probes for my Eico VTVM. That I > know is obsolete and is only for CRT sets.   There are people working with HV   > but I dont have room for old tube television sets, even though it would > be nice having one of those antiques. But I dont really plan to do > anymore work on televisions.   Some old TVs are as small as radios eg Ekco TMB272.   > flat screen types now, and if they die, I will simply replace them, > unless its a simple repair such as a blown fuse, bad power switch or a > broken wire.   bad psu caps are often worth testing for   > The reason that most of the old wax capacitors have failed, is because > the bees wax was gotten from "Low Tech" bees!     NT

tubeguy@myshop.com: Jan 07 01:32PM -0600 I recently bought an old Eico 955 In circuit capacitor tester. It worked right away, but I am going to recap it. But there is a problem. The Calibrated dial knob wont clamp to the shaft. Someone apparently over tightened the set screw and cracked the part that fits around the 1/4" shaft. Someone also must have glued it, then broke it again. That only makes gluing it again a worse option because the old glue is gooped all over the pieces, so they wont fit together properly anymore.   Finding a replacement is likely not an option. Knob Part number - Eico 89678   How would you fix this?   I do have one thought. To carefully grind away the entire center part of that knob with a dremyl tool. Then take a new smallish knob with a set screw and drill out the 1/4" hole thru to the face of that knob, and use JB Weld to glue that new knob inside the old one. Of course the set screw has to line up with the original set screw hole. (there is room for a small knob inside). I might even have a solid aluminum knob that will fit in there, but I have to find them....   However, grinding out that center will be tricky and time consuming, since the new knob needs to be centered very precisely.

John-Del <ohger1s@gmail.com>: Jan 07 12:09PM -0800 > will fit in there, but I have to find them....   > However, grinding out that center will be tricky and time consuming, > since the new knob needs to be centered very precisely.         The knobs all look different, the number of shaft configurations is very limited...

Fox's Mercantile <jdangus@att.net>: Jan 07 03:04PM -0600 > However, grinding out that center will be tricky and > time consuming, since the new knob needs to be centered > very precisely.   Not hardly. Even at it's best, it was only +/- 10%   I would suggest grinding out the crack and old glue, then repairing the original knob with JB Weld. Allow 24 hours for it to set up correctly.       -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com

Jeff Liebermann <jeffl@cruzio.com>: Jan 07 02:20PM -0800 >will fit in there, but I have to find them....   >However, grinding out that center will be tricky and time consuming, >since the new knob needs to be centered very precisely.   A few questions:   1. Which knob? <https://c1.staticflickr.com/4/3834/11055642634_e5daa78fe7_b.jpg>   2. What part of the knob is cracked? Is it the plastic part or the brass center insert? I haven't seen too many knobs without this brass insert as threading the plastic doesn't last very long on small diameter knobs.   I'll assume it's the brass insert. These are very much the same for all similar sized knobs that use a 1/4" dia shaft. I've actually done what you're proposing. I used a lathe to insure that everything was centered. Instead of trying to totally drill out the brass insert, I used a smaller drill (or end mill) that left a thin brass annular ring. I removed that with a pair of pliers.   The replacement brass insert was provided by a random knob from my collection. I inserted a 1/4" steel rod into the knob, gouged two grooves 180 degrees apart in the plastic (being careful to NOT hit the brass insert), and split open the knob.   Since both the plastic knobs and brass inserts were knurled, there was no way these were going to fit together without some modification. After some careful measurement, I put the original knob back into the lathe, and enlarged the hole slightly so that the new brass insert would fit. I then roughed up the plastic with sandpaper to give the glue something to grab onto. I stuffed a grease covered steel (not brass) screw into the set screw hole, smeared the brass insert with epoxy, and let it harden. The nylon screw was easily removed, but if there has been some difficulty, I could easily have removed it with a little brute force.   Good luck. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

whit3rd <whit3rd@gmail.com>: Jan 08 01:44AM -0800 > I recently bought an old Eico 955 In circuit capacitor tester. ... Someone apparently over > tightened the set screw and cracked the part that fits around the 1/4" > shaft.   A lathe and some aluminum to make a metal fitting, and some creative hollowing-out of the old knob, can fix it. Old plastic with cracks and glue just won't be a part of the solution (it needn't look like the original, IMHO).   If the shaft is fully round, consider a lock fitting as used on old trimpots: the knob can grab that shaft like a collet, but still come off with the right wrenches.

Tim R <timothy42b@aol.com>: Jan 07 07:54PM -0800 Okay, this is a 3 year old post, but it's MY 3 year old post.   Just out of curiosity, I tried something. I was cleaning up in the basement, and about to throw this thing out.   But first, I opened it up. Obviously I'd not done that before, because I had trouble doing it.   Anyway, I sprayed contact cleaner into every switch and worked them a bit.   Much to my surprise, it seems to be working on inputs now instead of outputs. It's the perfect size for my main internet laptop, so maybe it's a keeper. For now.

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