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#1
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![]() "Jay in the Mojave" wrote in message ... Hello Jimmie D: Ok good deal, yeah thats what I was talking about. My Sonic Cushion only used one light bulb, but that was for a old Johnson 350, 2 channel SSB only transistorized radio I used back in the 60's and 70's. Yes you needed to turn up the volume, then turn up the pot, and it worked quit well. I will have to try the two GE 47 bulbs and 5 ohm resistors and see what happens. Another thing we use to do was install two diodes cross polarized across the speaker terminals to soften the blast from a old high voltage tube rig that, sent a blast of voltage when the radio was unkeyed. Like a General Radiotelephone Super MC-11A. Thanks for the reply, Ah the memeories. Jay in the Mojave Charlie Alpha 5 Jimmie D wrote: Hi Jay , yeah I remeber those as an automatic volume control. Boy that was back in the 60's. I know I can date it back to between probably 67 and 69 when I first heard of it because I used one on my old Hallicrafter. The Halicrafter had AVC but this worked better for keeping you from getting blastedd by a strong signal that suddenly appeared when you had everything cranked up to hear a weak signal. Bulb would have to be in series and resistor in paralell because the bulbs resistance goes up whenever more current flows through it. If it works it must be right.. That is to say I dont remember either but I do remember it using two bulbs and the model I built was to be used with headphones. You had to crank the volume on the radio way up and then use a control on the box to adjust it to listenng level. Ok I found something that is just opposite what you wanted, I dont do ascii drawings so I will have to discribe it to you. Imagine a bridge circuit made of two #47 bulbs and two 5 ohms resistors. They are wired so the resistors dont connet to each other and the bulbs dont connect to each other but the bulbs do connect to the resistors. Input is through a pair of opposite corners of the bridge and output is through the other pair of opposite corners. At first I thought that you could reverse the position of the resistors and diodes to get what you wanted but after describing it I realized you would still have exactly the same circuit. Cicuit is in CBers Handybook Have you thought about putting a photo resistor in paralell with or replacing your resistor, light from the bulb wuold casue the resistance to decrease this should make the circuit more responsive. Its been a long time since I played with photoressitors so I dont remember what kind of resistance range they have. If they get low enough this could work pretty decent. I never thought that trying to do this on an 8 ohm circuit was such a great idea. Doing it at sayy 100 ohms might be better using a lower wattage bulb than the #47. Even at 8 ohms I thought a 3 volt flashlight bulb may do better. I never tried these ideas though because I took another route building my own select-o-ject and incorporating an AVC circuit into it. |
#2
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Hello Jimmie D:
No I didn't think of that! Maybe worth a try. I have a good friend on 40 that is going to send me a custom circuit that is supposed to do all this, and has a smart squelch to. We will see. Jay in the Mojave Jimmie D wrote: Have you thought about putting a photo resistor in paralell with or replacing your resistor, light from the bulb wuold casue the resistance to decrease this should make the circuit more responsive. Its been a long time since I played with photoressitors so I dont remember what kind of resistance range they have. If they get low enough this could work pretty decent. I never thought that trying to do this on an 8 ohm circuit was such a great idea. Doing it at sayy 100 ohms might be better using a lower wattage bulb than the #47. Even at 8 ohms I thought a 3 volt flashlight bulb may do better. I never tried these ideas though because I took another route building my own select-o-ject and incorporating an AVC circuit into it. |
#3
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Jay in the Mojave wrote:
I have a good friend on 40 that is going to send me a custom circuit that is supposed to do all this, and has a smart squelch to. We will see. Smart squelch? Please explain... www.telstar-electronics.com |
#4
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Hello Brian:
The Smart Squelch is supposed to be smart, just as its said! That is the squelch will open or turn on the receiver audio when a signal is received in the receivers IF. A separate pick off of the IF RF is sampled and then its supposed to only open the Squelch when there is a real signal, and is not supposed to work on noise, bleed over, static and such. The Smart Squelch is supposed to be able to discern between noises and a real RF signal. And its advertised as having a very high percentage of success, being able to only open the receiver with a rf signal and not noise. I built a Analog Smart Squelch back in the 80's for my Motorola System 500 Mobile SSB/AM CB Radio. (which all ready had a active Motorola noise canceling circuit in the IF Section) It worked real well. It was great driving down the freeway and not hearing motor noise, like setting at home. The Smart Squelch came from a article in a magazine, and I bought the kit and put it together. But this new circuit is supposed to be digital. I haven't seen it yet. But I know a lot of guys are using the Heil, Alpha Delta, and others External Speakers with DSP for extra noise cancelling. I have a Heil DSP External Speaker, and it works great, just need a smart squelch to go with it. Jay in the Mojave Telstar Electronics wrote: Jay in the Mojave wrote: I have a good friend on 40 that is going to send me a custom circuit that is supposed to do all this, and has a smart squelch to. We will see. Smart squelch? Please explain... www.telstar-electronics.com |
#5
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You may have to show off those kredentials again, Jay. I know I always
enjoy seeing them. Jay in the Mojave wrote: But this new circuit is supposed to be digital. I haven't seen it yet. |
#6
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![]() "Jay in the Mojave" wrote in message ... Hello Brian: The Smart Squelch is supposed to be smart, just as its said! That is the squelch will open or turn on the receiver audio when a signal is received in the receivers IF. A separate pick off of the IF RF is sampled and then its supposed to only open the Squelch when there is a real signal, and is not supposed to work on noise, bleed over, static and such. The Smart Squelch is supposed to be able to discern between noises and a real RF signal. And its advertised as having a very high percentage of success, being able to only open the receiver with a rf signal and not noise. I built a Analog Smart Squelch back in the 80's for my Motorola System 500 Mobile SSB/AM CB Radio. (which all ready had a active Motorola noise canceling circuit in the IF Section) It worked real well. It was great driving down the freeway and not hearing motor noise, like setting at home. The Smart Squelch came from a article in a magazine, and I bought the kit and put it together. But this new circuit is supposed to be digital. I haven't seen it yet. But I know a lot of guys are using the Heil, Alpha Delta, and others External Speakers with DSP for extra noise cancelling. I have a Heil DSP External Speaker, and it works great, just need a smart squelch to go with it. Jay in the Mojave Telstar Electronics wrote: Jay in the Mojave wrote: I have a good friend on 40 that is going to send me a custom circuit that is supposed to do all this, and has a smart squelch to. We will see. Smart squelch? Please explain... www.telstar-electronics.com I remember something that use a "bucket brigrade" audio delay line in a sqeich circuit in late 70s or early 80s. The audio was delayed a few milliseconds so the hardware would have time to analyse the signal to see if it should be squelched or not. Is this what yu are talking about. Probably a piece of cake for DSP. My first experience with DSP was in the Air Force. I was sent to school on this new modem and endured a month of theory on how modems worked all built around analog devices. In reality this thing was just a RISC computer attached to D/A and A/D converters. The only thing analog about it was a couple of op amps used on the input and output.. The modem itself was tiny but the cabinet it was in was huge. I guess it had to be this way for all the human interface that was needed. |
#7
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Jimmie D wrote:
"Jay in the Mojave" wrote in message ... Hello Brian: The Smart Squelch is supposed to be smart, just as its said! That is the squelch will open or turn on the receiver audio when a signal is received in the receivers IF. A separate pick off of the IF RF is sampled and then its supposed to only open the Squelch when there is a real signal, and is not supposed to work on noise, bleed over, static and such. The Smart Squelch is supposed to be able to discern between noises and a real RF signal. And its advertised as having a very high percentage of success, being able to only open the receiver with a rf signal and not noise. I built a Analog Smart Squelch back in the 80's for my Motorola System 500 Mobile SSB/AM CB Radio. (which all ready had a active Motorola noise canceling circuit in the IF Section) It worked real well. It was great driving down the freeway and not hearing motor noise, like setting at home. The Smart Squelch came from a article in a magazine, and I bought the kit and put it together. But this new circuit is supposed to be digital. I haven't seen it yet. But I know a lot of guys are using the Heil, Alpha Delta, and others External Speakers with DSP for extra noise cancelling. I have a Heil DSP External Speaker, and it works great, just need a smart squelch to go with it. Jay in the Mojave Telstar Electronics wrote: Jay in the Mojave wrote: I have a good friend on 40 that is going to send me a custom circuit that is supposed to do all this, and has a smart squelch to. We will see. Smart squelch? Please explain... www.telstar-electronics.com I remember something that use a "bucket brigrade" audio delay line in a sqeich circuit in late 70s or early 80s. The audio was delayed a few milliseconds so the hardware would have time to analyse the signal to see if it should be squelched or not. Is this what yu are talking about. Probably a piece of cake for DSP. My first experience with DSP was in the Air Force. I was sent to school on this new modem and endured a month of theory on how modems worked all built around analog devices. In reality this thing was just a RISC computer attached to D/A and A/D converters. The only thing analog about it was a couple of op amps used on the input and output.. The modem itself was tiny but the cabinet it was in was huge. I guess it had to be this way for all the human interface that was needed. Hello Jimmie D: Oh really, now thats interesting, the "bucket brigade" type delayed signal for processing. Yeah I would think so, DSP that is now working at the IF Frequencies should be able to handle all that. Yeah I am sure the Modem must be able to account for data from noise or other unwanted voltages seen. I am no Modem expert but your description sounds like typical of over done military hardware. Maybe the engineers wanting it to look like something big as it really didn't need to be. Trying to sell the hardware, as compared to having to deploy with a bunch of stuff that takes up too much space on a military transport aircraft. Thats where the military needs to hire a separate maintenance consultant group, not looking for a star placed next to their name. I think we have only seen the tip of the Ice Burg here with DSP (Digital Signal Processing). My old used Icom 746 Pro HF radio, is a first generation DSP radio. I am able to adjust the Radio's IF (Intermedent Frequency) Filters at a snap of a switch. Its noise reduction is fantastic. Stations on USB can almost be rejected when monitoring LSB. I would think more new wiz bang stuff is coming for DSP. Jay in the Mojave Kreediantials: Rock & Roll fan, got both kinds of music Owner 1967 Ford F250 4x4 Truck, no smog ****, has Hipo 460 CI Engine, has worlds loudest PA System, great for oldie but goodie night at the drive ins, or just wanting some normal person to get out of the way. 5 Kollege credits, 3 for passing, 2 for leavin early! Got new gas operated Dryer, now got unsed 220 Volt plug for big Linear, don't have to pull out Ma's oven to get 220 Volts no more, she don't mind the big cord going thru the Kitchen into the washer and dryer room from the living room Happy to be alive and in good health, some folks don't have that blessing. |
#8
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Jay in the Mojave wrote:
The Smart Squelch is supposed to be able to discern between noises and a real RF signal. This is the key. I would certainly like to know how this is accomplished. Seems to me this would be a complicated problem. www.telstar-electronics.com |
#9
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Hello TE:
Yes agreed. I don't have a clue. But somehow its supposed to be able to see the difference. And it can't be perfect, as everyone voice is different, and there has to be a Gazillion types of noises out there! My computer power supply had to engineered to generate noises and trash in the RF Spectrum. I shielded it, added in filters, grounded the computer like a radio, all helped but was not the cure. A year ago the computer power supply died. The Computer Tech Dude said it was the wrong kind, too small. OH Good!. Now with a modern larger power supply, only the hand held will pick up noises when near the computer, not out in the street. I could always tell when the kid was on the computer from the radio picking up noise from the driveway. Jay in the Mojave Telstar Electronics wrote: Jay in the Mojave wrote: The Smart Squelch is supposed to be able to discern between noises and a real RF signal. This is the key. I would certainly like to know how this is accomplished. Seems to me this would be a complicated problem. www.telstar-electronics.com |
#10
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![]() "Jay in the Mojave" wrote in message ... Hello TE: Yes agreed. I don't have a clue. But somehow its supposed to be able to see the difference. And it can't be perfect, as everyone voice is different, and there has to be a Gazillion types of noises out there! My computer power supply had to engineered to generate noises and trash in the RF Spectrum. I shielded it, added in filters, grounded the computer like a radio, all helped but was not the cure. A year ago the computer power supply died. The Computer Tech Dude said it was the wrong kind, too small. OH Good!. Now with a modern larger power supply, only the hand held will pick up noises when near the computer, not out in the street. I could always tell when the kid was on the computer from the radio picking up noise from the driveway. Jay in the Mojave Telstar Electronics wrote: Jay in the Mojave wrote: The Smart Squelch is supposed to be able to discern between noises and a real RF signal. This is the key. I would certainly like to know how this is accomplished. Seems to me this would be a complicated problem. www.telstar-electronics.com I had the same problem using a computer power supply. I t really quietened off after putting some small caps across the rectifiers. You have to remember there are 2 sets of rectifiers. One changes the 120 or 240 vac to 300volts dc or so, this is sent to a switcher where it is turned into AC again then rectified again. I think the caps were .001 for the 60hz part and and .0001 for the switched part. These values are a guess as it has been a while since I did this. I dont think the newer ones have this problem. I also saw where it is possible to rewire computer power supplies so you can get something on the order of 50 volts at 10 amps. The one I saw took rewiring the transformer with a new secondary and maintaing the 5 volt winding for regulation. I want to get back to this, sounds like it would make a good power supply for a FET amp. |
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