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Posted: 5/13/2021 11:47:33 AM EDT
I haven't even been on HF two weeks yet, and I just ordered an Acom 1010 amplifier.
 What do I need to connect this thing to an ICOM IC-7300? I also realized a few moments ago that it is set up for either 120V or 240V and doesn't ship with a plug. Which voltage should I choose? |
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Posted: 5/13/2021 11:49:54 AM EDT
[#1]
I’m a dummy/newbie but aren’t you plugging it into a 120v outlet most likely?
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Posted: 5/13/2021 12:02:19 PM EDT
[#2]
Wow! Where'd you buy it?
I imagine that eventually, I will end up with an amp, but not for a while, as they are not cheap and I am still having fun with how far my current (ha) hundred watts reaches. I'm not in a hurry. |
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Posted: 5/13/2021 12:19:27 PM EDT
[#3]
Quote HistoryQuoted: I’m a dummy/newbie but aren’t you plugging it into a 120v outlet most likely? I have an unused 220V breaker in my fuse panel, and can run a new line if a 220V receptacle is a better choice. |
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Posted: 5/13/2021 12:20:53 PM EDT
[#4]
Go with 240 VAC if you already have an outlet in your shack and don't plan to take your amp anywhere else with you.
It should work just fine on 120 VAC as long as it uses a dedicated circuit and a breaker (15 or 20 amps). It allows 15% voltage variations. So, a 120 VAC line will be quite sufficient for the amp. Just don't plug anything else in that 120 VAC circuit. ACOM makes one of the best amps, if not the best. Quality and engineering are excellent. It's VERY easy to operate. No guessing, no "dipping". Just use the TRI indicator and be done with it in seconds. It's not like tuning an Ameritron. There is no ALC connection. The amp is smart and protected. Just connect the PTT (TX GND) to key the amp and enjoy. Set TX Delay in the radio for 5-10 ms to avoid hot switching. The amp can detect hot switching and will switch to a bypass mode to save it's components from damage. MIne is a 1000 model. I push it easily to 1200 - 1300 watts with zero issues. 4CX800A (GU74B) tubes are of high quality and very robust but cheap. I see them on Ebay for $100, brand new. One tube will last for a looooooong time. I run mine hard and have used it a lot. It still runs like new, 7 years later. |
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Posted: 5/13/2021 12:27:40 PM EDT
[#5]
Quote HistoryQuoted: Wow! Where'd you buy it? I imagine that eventually, I will end up with an amp, but not for a while, as they are not cheap and I am still having fun with how far my current (ha) hundred watts reaches. I'm not in a hurry. I got it from HRO. Even though I've made QSO's with 30 countries, I've had my head stomped in enough pile-ups already. The finally straw was I heard a guy in Argentina calling CQ last night like we were in the same room, and even without a pile-up, he couldn't hear me.
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Posted: 5/13/2021 12:29:22 PM EDT
[#6]
Quote HistoryQuoted: I have an unused 220V breaker in my fuse panel, and can run a new line if a 220V receptacle is a better choice. It's rated at 1200VA for the service so that's only 10 amps @ 120v. You can get that with #12 wire on a 120v receptacle unless there is a lot of other stuff on the circuit (i.e. microwave, hair dryer, etc.). I would try it that way first and if necessary swap it around to 240v later. My Ameritron amp is very similar and I run if from a 120v circuit without any problems. |
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Posted: 5/13/2021 12:38:18 PM EDT
[#7]
Quote HistoryQuoted: There is no ALC connection. The amp is smart and protected. Just connect the PTT (TX GND) to key the amp and enjoy. Quote HistoryQuoted: There is no ALC connection. The amp is smart and protected. Just connect the PTT (TX GND) to key the amp and enjoy. That's gibberish to me. Set TX Delay in the radio for 5-10 ms to avoid hot switching. The amp can detect hot switching and will switch to a bypass mode to save it's components from damage. I assume that I can find this in my settings? |
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Posted: 5/13/2021 12:46:36 PM EDT
[#8]
Quote HistoryQuoted: It's rated at 1200VA for the service so that's only 10 amps @ 120v. You can get that with #12 wire on a 120v receptacle unless there is a lot of other stuff on the circuit (i.e. microwave, hair dryer, etc.). I would try it that way first and if necessary swap it around to 240v later. Sometimes the breaker my microwave is on pops if we run it and the George Forman grill simultaneously.  This house is wired weird -- the breakers don't control separate rooms. Instead, one breaker may shut off a receptacle in the kitchen, one in the living room, and one in the hallway, etc. I hate that.
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Posted: 5/13/2021 12:51:41 PM EDT
[#9]
If 240v is an option then that is most efficient electrically.
so what antenna are you getting to reach us? 
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Posted: 5/13/2021 12:55:00 PM EDT
[#10]
Quote HistoryQuoted: Sometimes the breaker my microwave is on pops if we run it and the George Forman grill simultaneously. This house is wired weird -- the breakers don't control separate rooms. Instead, one breaker my shut off a receptacle in the kitchen, one in the living room, and one in the hallway, etc. I hate that.Quote HistoryQuoted: Quoted: It's rated at 1200VA for the service so that's only 10 amps @ 120v. You can get that with #12 wire on a 120v receptacle unless there is a lot of other stuff on the circuit (i.e. microwave, hair dryer, etc.). I would try it that way first and if necessary swap it around to 240v later. Sometimes the breaker my microwave is on pops if we run it and the George Forman grill simultaneously. This house is wired weird -- the breakers don't control separate rooms. Instead, one breaker my shut off a receptacle in the kitchen, one in the living room, and one in the hallway, etc. I hate that.I had a guy suggest that spread breaker approach in my garage to avoid tripping using multiple tools at once. i only got two hands so I did it in sections on the wall and bench like most would. No nested spread stuff to hunt later. You would really want to label your circuits if you did that. I get putting an outlet or two on the other face of a wall to save wire but it is certainly an economy thing to do these days. I did get burned once by my memory on the other side of the wall thing in the garage. First circuit on a wall went dead. I was hunting the first box which should have been a GFCI,.....no, not on the front wall either. Cycled untripped breaker. nope not it. Started pulling outlets to check with meter. First one definitely dead, breaker in box is hot. Shouldn’t be anything between the breaker and that string of outlets, iIts late, get pissed go have a beer and and go to bed. Woke up at 2am with the epiphany/recollection. Since code required an outside GFCI outlet, I had one just on the other side of the “bad” outlet that was actually the number one outlet protecting the rest down the circuit inside the structure. edit, and I did get up in the pouring rain, and went outside in my bathrobe carrying a flashlight and looked at the gfci, yep, tripped (from sparky angle grinder). Put everything back in order in the morning. |
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Posted: 5/13/2021 1:07:13 PM EDT
[#11]
Quote HistoryQuoted: So what antenna are you getting to reach us? If I won't melt it, I'll use my dipole until I can save more money. I don't know what happened with our group text the other night, but my phone went haywire! It kept showing multimedia boxes from you guys that said downloading but never did. I started getting texts that said they were from me but weren't. I finally had to delete the group text and temporarily block you guys' phone numbers to make it stop. LOL! Seriously. My phone has never had any problems before that conversation. |
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Posted: 5/13/2021 1:12:40 PM EDT
[#12]
Ha I am having phone fits today....everything is going to VM directly. Half a dozen back and forth phone tags with my eye doctor’s office. Finally got a human connection besides a message taker and answer at noon. actually talked to the doctor himself!
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Posted: 5/13/2021 1:26:22 PM EDT
[#13]
Quoted: If I won't melt it, I'll use my dipole until I can save more money. I don't know what happened with our group text the other night, but my phone went haywire! It kept showing multimedia boxes from you guys that said downloading but never did. I started getting texts that said they were from me but weren't. I finally had to delete the group text and temporarily block you guys' phone numbers to make it stop. LOL! Seriously. My phone has never had any problems before that conversation. Clearly, this is operator error.  Quoted: Ha I am having phone fits today....everything is going to VM directly. Half a dozen back and forth phone tags with my eye doctor’s office. Finally got a human connection besides a message taker and answer at noon. actually talked to the doctor himself! My phone is working normally. I have made a voice call and sent/received texts since that group text, so I don't know what's going on. |
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Posted: 5/13/2021 1:34:54 PM EDT
[#14]
Quote HistoryQuoted: My phone is working normally. I have made a voice call and sent/received texts since that group text, so I don't know what's going on. It's because you're the infected one. 
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Posted: 5/13/2021 1:47:30 PM EDT
[#15]
Quoted: I haven't even been on HF two weeks yet, and I just ordered an Acom 1010 amplifier. What do I need to connect this thing to an ICOM IC-7300? I also realized a few moments ago that it is set up for either 120V or 240V and doesn't ship with a plug. Which voltage should I choose?  I've been running my KPA500 off of 110 (or 115, or 120, I can't keep track of what the standard is anymore!) and it works fine, as will yours as long as you use a dedicated circuit, as others have already said. However, it will run a little cooler and easier from a 220 (or 230 or 240  ) line if you can arrange it. It's no big deal either way. Get it going on 110 and you can always optimize later. However...you say your house has some oddities associated with the way circuits are arranged. If you don't sort out a dedicated circuit for this amp, 110 or 220, you will probably have trouble. In the short term you may have to run an extension cord from another outlet--don't laugh, I've done it myself in the past! This amp will change your life, wait and see, it will seriously improve your enjoyment of the hobby  BUT...now for the million dollar question: do you need to use an antenna tuner, either the internal 7300 tuner or another one, with your antenna? If so, then you are also going to need one that can handle the output power of the amplifier. |
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Posted: 5/13/2021 1:49:12 PM EDT
[#16]
Quote HistoryQuoted: BUT...now for the million dollar question: do you need to use an antenna tuner, either the internal 7300 tuner or another one, with your antenna? If so, then you are also going to need one that can handle the output power of the amplifier. The amp says its built in matching can handle up to 3:1. |
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Posted: 5/13/2021 2:04:10 PM EDT
[#17]
Quote HistoryQuoted: BUT...now for the million dollar question: do you need to use an antenna tuner, either the internal 7300 tuner or another one, with your antenna? If so, then you are also going to need one that can handle the output power of the amplifier. I'm running a 20M dipole at the moment, and it is resonant and doesn't even require tuning from my IC-7300. As for voltages, I call them 110 and 220, but no one else seems to these days. |
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Posted: 5/13/2021 2:08:51 PM EDT
[#18]
 Mr Mom 220 221 whatever it takes |
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Posted: 5/13/2021 3:26:57 PM EDT
[#19]
Quote HistoryQuoted: Sometimes the breaker my microwave is on pops if we run it and the George Forman grill simultaneously. This house is wired weird -- the breakers don't control separate rooms. Instead, one breaker my shut off a receptacle in the kitchen, one in the living room, and one in the hallway, etc. I hate that.Quote HistoryQuoted: Quoted: It's rated at 1200VA for the service so that's only 10 amps @ 120v. You can get that with #12 wire on a 120v receptacle unless there is a lot of other stuff on the circuit (i.e. microwave, hair dryer, etc.). I would try it that way first and if necessary swap it around to 240v later. Sometimes the breaker my microwave is on pops if we run it and the George Forman grill simultaneously. This house is wired weird -- the breakers don't control separate rooms. Instead, one breaker my shut off a receptacle in the kitchen, one in the living room, and one in the hallway, etc. I hate that.That is normal |
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Posted: 5/13/2021 3:35:29 PM EDT
[#20]
Quote HistoryQuoted: I'm running a 20M dipole at the moment, and it is resonant and doesn't even require tuning from my IC-7300. As for voltages, I call them 110 and 220, but no one else seems to these days. Nominal voltage nomenclature seems to change over the years for no apparent reason. For a while they will all show 110v, then 115, then 120. Keep in mind that they are AC voltages and the waveform is a sine wave, not a square wave, therefore the true instantaneous voltage is changing constantly at a rate of 60 Hz. I've always referred to it as 120 or 240 VAC however one of the electrical engineers I work with refers to it as 120 / 230 VAC which is an odd mixture. Pick one you like and go with it, everyone will know what you mean. As to your amp, the specs show 1200VA which is simply "Volt Amps" or volts times amps*. The NEC requires that the wire has 25% more ampacity than the overcurrent protection device (fuse or circuit breaker) so #12 THHN wire, which is rated for 25 amps, will require a circuit breaker of 20 amps maximum. Your amp is pulling 10 amps wide open so you are at half the ampacity of a 120V, 20 amp circuit. Unless there is an additional 10 amp load on the circuit you'll be fine. My Ameritron amp is a 600 watt solid-state amp and I run it from a 120V circuit with no issues at all. I also have an old Heathkit SB220 (2x 3-500Z tube finals) which is a 2kw (input) amplifier and I ran it for a long time on the same circuit although never wide open. As was mentioned above you'll get slightly better efficiency running it at 240V but if you don't want to pull a new circuit you can get by just fine without it. * The term "Volt Amps" is used to indicate that the circuit is an AC circuit. While the formula is the same as Watts on a DC (voltage x amps) circuit the fact that the voltage of an AC circuit is constantly changing makes a difference. Converting between Watts and Volt Amps includes a multiplier for "Power Factor". We normally use 85% so a 100 Watt circuit would convert to 100/0.85 = 117.6 Volt Amps. |
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Posted: 5/13/2021 3:49:31 PM EDT
[#21]
Quote HistoryQuoted: The amp says its built in matching can handle up to 3:1. As it happens the question is moot since he has reported that he has a single band, resonant dipole, and that's all he's running right now. But in the future who knows? |
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Posted: 5/13/2021 5:45:47 PM EDT
[#22]
Quote HistoryQuoted: Nominal voltage nomenclature seems to change over the years for no apparent reason. For a while they will all show 110v, then 115, then 120. Keep in mind that they are AC voltages and the waveform is a sine wave, not a square wave, therefore the true instantaneous voltage is changing constantly at a rate of 60 Hz. I've always referred to it as 120 or 240 VAC however one of the electrical engineers I work with refers to it as 120 / 230 VAC which is an odd mixture. Pick one you like and go with it, everyone will know what you mean. As to your amp, the specs show 1200VA which is simply "Volt Amps" or volts times amps*. The NEC requires that the wire has 25% more ampacity than the overcurrent protection device (fuse or circuit breaker) so #12 THHN wire, which is rated for 25 amps, will require a circuit breaker of 20 amps maximum. Your amp is pulling 10 amps wide open so you are at half the ampacity of a 120V, 20 amp circuit. Unless there is an additional 10 amp load on the circuit you'll be fine. My Ameritron amp is a 600 watt solid-state amp and I run it from a 120V circuit with no issues at all. I also have an old Heathkit SB220 (2x 3-500Z tube finals) which is a 2kw (input) amplifier and I ran it for a long time on the same circuit although never wide open. As was mentioned above you'll get slightly better efficiency running it at 240V but if you don't want to pull a new circuit you can get by just fine without it. * The term "Volt Amps" is used to indicate that the circuit is an AC circuit. While the formula is the same as Watts on a DC (voltage x amps) circuit the fact that the voltage of an AC circuit is constantly changing makes a difference. Converting between Watts and Volt Amps includes a multiplier for "Power Factor". We normally use 85% so a 100 Watt circuit would convert to 100/0.85 = 117.6 Volt Amps. Quote HistoryQuoted: Quoted: I'm running a 20M dipole at the moment, and it is resonant and doesn't even require tuning from my IC-7300. As for voltages, I call them 110 and 220, but no one else seems to these days. Nominal voltage nomenclature seems to change over the years for no apparent reason. For a while they will all show 110v, then 115, then 120. Keep in mind that they are AC voltages and the waveform is a sine wave, not a square wave, therefore the true instantaneous voltage is changing constantly at a rate of 60 Hz. I've always referred to it as 120 or 240 VAC however one of the electrical engineers I work with refers to it as 120 / 230 VAC which is an odd mixture. Pick one you like and go with it, everyone will know what you mean. As to your amp, the specs show 1200VA which is simply "Volt Amps" or volts times amps*. The NEC requires that the wire has 25% more ampacity than the overcurrent protection device (fuse or circuit breaker) so #12 THHN wire, which is rated for 25 amps, will require a circuit breaker of 20 amps maximum. Your amp is pulling 10 amps wide open so you are at half the ampacity of a 120V, 20 amp circuit. Unless there is an additional 10 amp load on the circuit you'll be fine. My Ameritron amp is a 600 watt solid-state amp and I run it from a 120V circuit with no issues at all. I also have an old Heathkit SB220 (2x 3-500Z tube finals) which is a 2kw (input) amplifier and I ran it for a long time on the same circuit although never wide open. As was mentioned above you'll get slightly better efficiency running it at 240V but if you don't want to pull a new circuit you can get by just fine without it. * The term "Volt Amps" is used to indicate that the circuit is an AC circuit. While the formula is the same as Watts on a DC (voltage x amps) circuit the fact that the voltage of an AC circuit is constantly changing makes a difference. Converting between Watts and Volt Amps includes a multiplier for "Power Factor". We normally use 85% so a 100 Watt circuit would convert to 100/0.85 = 117.6 Volt Amps. It isn't just nomenclature for commercial power production and delivery, the voltage has actually changed over the years. The initial commercial power was 110 volts, then it was increased to 115 volts, I think for a short time it was also 117 volts. Then it transitioned I think in the late 1950s to 120 volts. Those were actual delivered voltages. If you buy any old ham tube gear that was designed for 110 volts and run them today, commercial power today is allowed a variance of 5%, so that 120 volts can be 126 volts and a piece of gear that was designed for 110 volts could easily be getting 16 volts more, which for a nominal 1000 volt B+ would mean an extra 146 volts or 1146 volts .That extra 16 volts can easily stress everything from tube filaments to transformers. Tube filaments are resistive, so if you apply more voltage, you get more current and therefore get more heat which shortens life on something that may or may not be that easy or cheap to replace. When I run my Hallicrafters transmitter and Receiver I run them on a variac at 110 volts to keep that from happening. |
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Posted: 5/13/2021 6:34:57 PM EDT
[#23]
Quote HistoryQuoted: ...Argentina calling CQ last night like we were in the same room, and even without a pile-up, he couldn't hear me. how high up is your dipole ? . |
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Posted: 5/13/2021 6:38:28 PM EDT
[#24]
Quote HistoryQuoted: how high up is your dipole ? . Somewhere between 30 and 40 feet in a tree. |
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Posted: 5/13/2021 7:26:44 PM EDT
[#25]
Unless I am mistaken, VA is the rating used for non power factor (unity/power factor 1:1) loads (pure resistive) like old fashioned light bulbs, resistance heaters and transformers, where watts and calculated power factor are used for motors.
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Posted: 5/13/2021 8:00:06 PM EDT
[#26]
Quote HistoryQuoted: You have downloaded and read the manual, right? This. RTFM while you await delivery. Acom 1010 All the previous advice is good, and Gyprat was spot on with his reply. I happen to have mine running on 110, and there is headroom on the circuit, but if I had a 220 circuit nearby to use, I would use it. The manual explains how to configure it for various line voltages. E.T.A. You'll should only need one RCA cable between the radio and amplifier (caveat emptor - check the radio manual for what "transmit to ground" connector is on back of the radio.) The Acom should be a single RCA input (Key Input.) And like Gyprat stated, there isn't an ALC port, so you don't make that connection. It's all in the manuals brother... 
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Posted: 5/13/2021 8:11:19 PM EDT
[#27]
Quote HistoryQuoted: And that's all well and good if he was only relying on the 7300 internal tuner, which can also match 3:1. However, what if he was using an external tuner with the 7300 and needed more range than that? Hence my question. As it happens the question is moot since he has reported that he has a single band, resonant dipole, and that's all he's running right now. But in the future who knows? Quote HistoryQuoted: Quoted: The amp says its built in matching can handle up to 3:1. As it happens the question is moot since he has reported that he has a single band, resonant dipole, and that's all he's running right now. But in the future who knows? Playing with mismatched loads and tuners isn't generally a good plan with an amplifier. |
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Posted: 5/13/2021 8:39:20 PM EDT
[#28]
Quote HistoryThanks! I'd say that I'd better hurry and read it since tracking is calling for a Saturday delivery, but more than likely I'll go the 240V route, so I have a little time. I figure something else is probably on the same circuit as each of the outlets in the room that will become my ham shack, so it's best to run a new line. I have an unused 240V breaker in the panel, so I may as well put it to good use. I just need to find someone who can connect my new line to the breaker. |
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Posted: 5/13/2021 9:02:21 PM EDT
[#29]
Quote HistoryQuoted: Playing with mismatched loads and tuners isn't generally a good plan with an amplifier. Are you trying to say that you should never use an antenna tuner with an amplifier? |
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Posted: 5/13/2021 9:14:30 PM EDT
[#30]
Have you ever operated a transmitter with a Pi network output? If not, search the Internet and find out how to operate one before your amp arrives. The amplifier instructions will tell you how, but it's a good idea to get a heads-up beforehand so there will be no (or at least few) surprises.
The Pi network functions as an output matching device, ie, an antenna tuner. Depending on the design, they can have a wide range of load matching capability. Quoted: Are you trying to say that you should never use an antenna tuner with an amplifier? Not at all. The best way to use one is to bypass the amp and adjust the tuner for minimum SWR using just the power from the exciter. To get the initial settings, cut back the power of the exciter also. Then log these setting for each band so you can quickly return to them. |
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Posted: 5/13/2021 9:50:26 PM EDT
[#31]
Quote HistoryQuoted: ... I heard a guy in Argentina calling CQ last night like we were in the same room, and even without a pile-up, he couldn't hear me. pretty soon, you'll be able to work Argentina with a 25watt mobile on a regular basis. . . all you need are some more sunspots he may have simply been ignoring you because Argentina to USA is pretty common with trans-equatorial propagation. . |
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Posted: 5/13/2021 10:15:12 PM EDT
[#32]
Here is a good explanation of how the Pi-network was derived and how it operates. It uses stuff you (should have) learned when studying for your General Class license.
 The Pi-Network |
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Posted: 5/13/2021 10:53:06 PM EDT
[#33]
That's not the highest power amp out there, but it's still an amp, so be mindful of components in your antenna system, end insulators, etc which will all be subject to higher voltages with the higher power. As an example, with a wire dipole at "barefoot" (100w) power levels, it's no problem to just make a loop in the end of the wire and tie a string to it. With an amplifier, you really want to use some kind of insulator at that junction. I wouldn't trust RG58 at that power level. Etc.
Quote HistoryQuoted: Are you trying to say that you should never use an antenna tuner with an amplifier? Quote HistoryQuoted: Quoted: Playing with mismatched loads and tuners isn't generally a good plan with an amplifier. Are you trying to say that you should never use an antenna tuner with an amplifier? Antennas that are very mismatched and used with wide-range tuners have very high voltages on the feedline. Add in an amplifier and insulation breakdown/damage, arcing, corona etc all become high probability. Along with that, almost all such antenna configurations are usually bad for common mode/RF in the shack/RFI problems. Increase by an order of magnitude with an amplifier and you're likely to cause yourself a lot of headaches as well as even potential safety/health issues from stray RF. |
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Posted: 5/14/2021 7:44:41 AM EDT
[#34]
Quote HistoryQuoted:Antennas that are very mismatched and used with wide-range tuners have very high voltages on the feedline. Add in an amplifier and insulation breakdown/damage, arcing, corona etc all become high probability. Along with that, almost all such antenna configurations are usually bad for common mode/RF in the shack/RFI problems. Increase by an order of magnitude with an amplifier and you're likely to cause yourself a lot of headaches as well as even potential safety/health issues from stray RF. 1. Use window or ladder line as your feed. Use a proper length for the freq's you want to operate on. 2. Mount the balun to the exterior of the house. 3. Use the highest power rated balun you can get. DX Engineering used to have 10KW rated baluns, now you can only buy 5KW rated baluns from them, but that should work. 4. Use a "current type" balun. 5. Add a good ferrite choke on the coax at the balun. 6. Use a remote tuner at the balun. 7. If you can't do (6), use LMR400 for the feedline to the shack location in the house. 8. Make sure your grounding and bonding of equipment is tip top. That said it's a moot point right now since the OP's antenna is resonant and he's using a coaxial feedline. Although you do make a good point that 1KW is sporty for RG58. |
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Posted: 5/14/2021 7:55:17 AM EDT
[#35]
Should I be running a choke? I have a #31 ferrite ring and RG-400 from which I could get what I think is the required 13 turns. I'm running LMR-400 coax for the feedline.
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Posted: 5/14/2021 12:48:30 PM EDT
[#36]
A choke is always cheap insurance against shield currents.
I prefer a choke made out of a half dozen snap-on ferrites in a bunch as close to the antenna as I can get them. Type 31 material is what you want as it is optimized for HF frequency absorption. I use Fair-Rite brand ferrite snap-on's. These are the ones you want for LMR400: https://www.digikey.com/en/products/detail/fair-rite-products-corp/0431164181/8593998 A few cable ties above and below them will keep them from sliding around. Then put some large diameter shrink sleeve over the top of them. Be cautious about buying ferrites. Some of the usual ham parts places mark them up considerably. And some don't specify if it's Type 31 material or not. I normally buy the actual Fair-Rite or Amidon part number I want from more serious electronics parts distributors like Digi-Key, Mouser or Newark so that I know exactly what I'm getting and it's exactly what I want. |
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Posted: 5/14/2021 1:45:19 PM EDT
[#37]
String of beads choke is a very inefficient use of ferrites, and with high power is a good way to melt something as it's hard to get enough impedance with them.
Multiple passes through a ferrite are an order of magnitude more effective. Here's some reading on chokes/baluns: http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf |
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Posted: 5/14/2021 4:21:09 PM EDT
[#38]
Quote HistoryQuoted: That's not the highest power amp out there, but it's still an amp... The difference between 700 Watts and 1500 Watts amounts to about 1/2 of a S-unit. |
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Posted: 5/14/2021 6:12:04 PM EDT
[#39]
Quote HistoryQuoted: That's gibberish to me. I assume that I can find this in my settings? Perhaps you should read your radio's and amp's user manuals on this subject. These are the things you must know before operating any amplifier/radio system. A dedicated circuit means that it's only used for one dedicated device or a system. It consists of a 15 or 20 amps breaker, electrical wire (cable) and a receptacle. If you have this, you should be good to go with 120 VAC. If you don't have it and need to run a new circuit, might as well install a dedicated 240 VAC line to the shack. It won't cost a lot more and you'll be able to use for a bigger amp if you ever decide to upgrade. Consult an electrician if you don't know how to do this yourself. For the amp connection, you'll need a 3' or 6' coax cable with PL-259 on both ends. An RG-8x or even RG-58 will do the job. Connect one end of the cable to ANTENNA connector on the radio and ANT IN on the amplifier. You'll need a single RCA cable with ends. It's the same cable used on stereos (LIne in, Line out etc). Connect one end to your radio's TX Out connector (TX GND or similar name as it varies by manufacturers) and the other end to TX GND on the amp. This will switch the amp to transmit when the radio is transmitting. That's it. Connect your antenna(s) to the ANT1 or ANT2 on the amp and you are good to go. Read up on RF safety. It's important when running high power. The amp can handle up to 3:1 SWR without an external tuner. I'm gonna shut up and no longer talk about the benefits of antennas, amps and antenna tuners. Enough was said about it and I don't feel like repeating myself every week as this subject comes up on this forum. Just a quick example. An antenna with 3 db more gain will put out twice the signal on the receiving end. Invest into antennas before investing into an amp. Amps are great and they do help a lot but antennas are much more important. Some of us can't have large antennas due to restrictions or lack of space. An amp is the next logical choice then. |
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Posted: 5/14/2021 6:33:26 PM EDT
[#40]
Quote HistoryQuoted: String of beads choke is a very inefficient use of ferrites, and with high power is a good way to melt something as it's hard to get enough impedance with them.
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Posted: 5/14/2021 6:42:43 PM EDT
[#41]
Quote HistoryQuoted: Perhaps you should read your radio's and amp's user manuals on this subject. These are the things you must know before operating any amplifier/radio system. A dedicated circuit means that it's only used for one dedicated device or a system. It consists of a 15 or 20 amps breaker, electrical wire (cable) and a receptacle. If you have this, you should be good to go with 120 VAC. If you don't have it and need to run a new circuit, might as well install a dedicated 240 VAC line to the shack. It won't cost a lot more and you'll be able to use for a bigger amp if you ever decide to upgrade. Consult an electrician if you don't know how to do this yourself. For the amp connection, you'll need a 3' or 6' coax cable with PL-259 on both ends. An RG-8x or even RG-58 will do the job. Connect one end of the cable to ANTENNA connector on the radio and ANT IN on the amplifier. You'll need a single RCA cable with ends. It's the same cable used on stereos (LIne in, Line out etc). Connect one end to your radio's TX Out connector (TX GND or similar name as it varies by manufacturers) and the other end to TX GND on the amp. This will switch the amp to transmit when the radio is transmitting. That's it. Connect your antenna(s) to the ANT1 or ANT2 on the amp and you are good to go. Read up on RF safety. It's important when running high power. The amp can handle up to 3:1 SWR without an external tuner. I'm gonna shut up and no longer talk about the benefits of antennas, amps and antenna tuners. Enough was said about it and I don't feel like repeating myself every week as this subject comes up on this forum. Just a quick example. An antenna with 3 db more gain will put out twice the signal on the receiving end. Invest into antennas before investing into an amp. Amps are great and they do help a lot but antennas are much more important. Some of us can't have large antennas due to restrictions or lack of space. An amp is the next logical choice then. Well said antenna is 90% of your station  |
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Posted: 5/15/2021 10:45:15 AM EDT
[#42]
Quote HistoryQuoted: Playing with mismatched loads and tuners isn't generally a good plan with an amplifier. Quote HistoryQuoted: Quoted: Quoted: The amp says its built in matching can handle up to 3:1. As it happens the question is moot since he has reported that he has a single band, resonant dipole, and that's all he's running right now. But in the future who knows? Playing with mismatched loads and tuners isn't generally a good plan with an amplifier. why not? I do it at 1500 watts, but usually stay at around 1kw |
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Posted: 5/16/2021 10:14:08 AM EDT
[#43]
Quote HistoryQuoted: A choke is always cheap insurance against shield currents. I prefer a choke made out of a half dozen snap-on ferrites in a bunch as close to the antenna as I can get them. Type 31 material is what you want as it is optimized for HF frequency absorption. I use Fair-Rite brand ferrite snap-on's. These are the ones you want for LMR400: https://www.digikey.com/en/products/detail/fair-rite-products-corp/0431164181/8593998 A few cable ties above and below them will keep them from sliding around. Then put some large diameter shrink sleeve over the top of them. Thanks for posting this. I was going to ask a question today, but this may be the answer I was looking for. Was not aware that I should have been choking the feed line. I've been having a random signal disturbance (primarily on 20m) that last for 30 minutes and then gone for hours at a time. Makes my waterfall look like this:  Attached FileAny chance a half dozen of those snap-on ferrites might help? If yes, should I add a few sections of choke along the line? My LMR-400 run is 150 feet. OP Congrats on your new amp! I can only dream about the success you've already had. I've only been able to hit 3 other countries to the south. I can't even get a sniff from Europe. But just finished my new antenna and hope it makes a difference. Sorry for the hi-jack. |
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Posted: 5/16/2021 11:14:31 AM EDT
[#44]
Does your water heater have solid state controls? Try turning off the circuit breaker feeding it the next time it happens.
When I changed out mine, I got one with the conventional mechanical thermostats just for that reason. |
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Posted: 5/16/2021 11:39:21 AM EDT
[#45]
Quote HistoryQuoted:Any chance a half dozen of those snap-on ferrites might help? If yes, should I add a few sections of choke along the line? My LMR-400 run is 150 feet. |
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Posted: 5/16/2021 12:00:00 PM EDT
[#46]
Quote HistoryQuoted: I wouldn't think so. They are to prevent shield currents from coming back into the station during transmit, not to fix interference being picked up by your antenna during receive. Quote HistoryQuoted: Quoted:Any chance a half dozen of those snap-on ferrites might help? If yes, should I add a few sections of choke along the line? My LMR-400 run is 150 feet. Chokes stop noise flowing from station out to the antenna on the coax shield just like they stop signal flowing back to the station from the antenna. Noise reduction is one of the main purposes of chokes. |
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Posted: 5/16/2021 12:21:34 PM EDT
[#47]
Quote HistoryQuoted: Does your water heater have solid state controls? Try turning off the circuit breaker feeding it the next time it happens. When I changed out mine, I got one with the conventional mechanical thermostats just for that reason. Great troubleshooting tip - will try. Thanks for the info guys. I'll choke the line regardless and keep searching for the noise source. |
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Posted: 5/16/2021 12:31:16 PM EDT
[#48]
Quote HistoryQuoted: Great troubleshooting tip - will try. Thanks for the info guys. I'll choke the line regardless and keep searching for the noise source. Quote HistoryQuoted: Quoted: Does your water heater have solid state controls? Try turning off the circuit breaker feeding it the next time it happens. When I changed out mine, I got one with the conventional mechanical thermostats just for that reason. Great troubleshooting tip - will try. Thanks for the info guys. I'll choke the line regardless and keep searching for the noise source. If you can identify the source of the noise, you can choke noise at the source also which will help significantly. |
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Posted: 5/16/2021 12:32:57 PM EDT
[#49]
Quote HistoryQuoted: Chokes stop noise flowing from station out to the antenna on the coax shield just like they stop signal flowing back to the station from the antenna. Noise reduction is one of the main purposes of chokes. Quote HistoryQuoted: Quoted: Quoted:Any chance a half dozen of those snap-on ferrites might help? If yes, should I add a few sections of choke along the line? My LMR-400 run is 150 feet. Chokes stop noise flowing from station out to the antenna on the coax shield just like they stop signal flowing back to the station from the antenna. Noise reduction is one of the main purposes of chokes. A choke of the type I describe at the antenna feedpoing will not stop an interfering signal that originates from a source outside of your station and only enters it through the antenna. If it could do that it would also eliminate desired signals as well. A choke at the antenna feedpoint is to deal with any currents induced by impedance mismatches during transmit. If you've got some local idiot with a grow operation in his basement, or a neighbor with an electrically noisy solar panel installation, or a malfunctioning transformer on a pole near you, and you think that these signals are inducing currents on the shield of your coaxial cable, then you need a separate common mode choke near the receiver end a quarter wavelength from the receiver. Ideally you use a choke at both locations for maximum performance. |
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Posted: 5/16/2021 2:41:53 PM EDT
[#50]
Quote HistoryQuoted: ...you need a separate common mode choke near the receiver end a quarter wavelength from the receiver. Ideally you use a choke at both locations for maximum performance. 1/4 Wavelength meaning 1/4 of the length of the coax cable, or 1/4 wavelength of my longest element - 80m? I'm using a DX Commander vertical antenna if that makes a difference. I'll work on the source this week and try and stop it there if possible. |
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