but when I switch to AM, RF power is automatically limited to 25W.
Of course. You probably actually already know why: The final amplifier in your transceiver is a linear amplifier. Linear amplifiers work great for SSB, CW, and the digital modes. But they really suck canal water on AM, where the best they can muster is about 33% efficiency. Modern SSB transceivers are not capable of 100 watts output on AM.
We can fix you up with a transmitter that will work efficiently on AM 11 meters. The Johnson Viking II comes to mind. Ahhhhh.... the classic pair of 6146 final amplifier tubes, plate modulated. Used one a lot in the early days. It was designed before 11 meters was ceded to Citizen's Band and it was designed to work there as well as 80-10.
Is this trackable by the government? Don't have any knowledge or experience with this sort of thing. Just curious.
Man, they catch EVERY electronic transmission, worldwide, every day, if you believe what they say. Yeah, they can hear it. And your phone calls., your credit card transactions, your posts here, and whatever you say with your phone in your pocket. They don’t NEED to snoop on your ham talk, but they can. There is no privacy, short of ditching anything electronic and disassociating from those who use it. If you aren’t crazy enough to do that, just live your life and don’t worry about it.
Many of the new radios use SDR (software-defined radio) receivers, and a number of them aren't heterodyned: which means that there's a digital sampler inside the radio that samples the signal coming in from the antenna at a rate that's at least twice the highest frequency tunable by the radio. On the 70cm band, for example, that's almost a billion samples per second. Then that stream of data is digitally processed to extract whatever signals you want to listen to.
But it's also the case that if you could send that billion-sample-per-second stream of data to persistent storage, you could come back to it at any later time and locate anything that had happened anywhere on the piece of spectrum from the lowest frequency the antenna could receive to half the sample rate.
I don't have the resources to keep a permanent archive of radio spectrum that grows at a billion samples per second; but you know why that is? Because I have to pay those resources to Uncle Sam so that he does.
(PS: Yes, if you had several such archives recorded from different locations, it's possible that you could DF (direction-find: locate geographically) a transmitter from the past.)
Last edited by Barak; 10/03/21.
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
But none of my HF radios will transmit on 11m at all, period. Key the mic, and the radio just grins at you. Why don't they give me transmit access to 11m and just restrict the power to 5W? If they're worried about me transmitting between channels, they could preset memories to the 40 CB channels the way they do to the 5 channels on the 60m band. It'd be easy to box me into legal operations with hardware restrictions. .
Might not be worth the cost and process of them to channelize frequencies and regulate power for one band when one can buy a cobra 29 for $115.
Yeah, but they've already obviously got the hardware functionality to do it, so it's just firmware; and if you've got decent volume, firmware is practically free.
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
but when I switch to AM, RF power is automatically limited to 25W.
Of course. You probably actually already know why: The final amplifier in your transceiver is a linear amplifier. Linear amplifiers work great for SSB, CW, and the digital modes. But they really suck canal water on AM, where the best they can muster is about 33% efficiency. Modern SSB transceivers are not capable of 100 watts output on AM.
Sure. And there's also the fact that AM transmitters have to spend power on two copies of the audio signal and one copy of the carrier, whereas SSB transmitters can spend the whole power budget on a single copy of the signal.
I'm not complaining about being limited to 25W on AM: I'm remarking on the radio's ability to automatically limit me. It has that capability; therefore it could use that capability to provide legal access to 11m for the price of a bit of firmware.
Hmm...now I'm wondering how hard it would be to hack the firmware.
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We can fix you up with a transmitter that will work efficiently on AM 11 meters. The Johnson Viking II comes to mind. Ahhhhh.... the classic pair of 6146 final amplifier tubes, plate modulated. Used one a lot in the early days. It was designed before 11 meters was ceded to Citizen's Band and it was designed to work there as well as 80-10.
I haven't been bitten by the vacuum-tube bug yet: I still like power transistors. Maybe if someday I get myself a big ol' linear amp, I'll wind up being seduced by the charms of a nicely-matched pair of output tubes; but for now none of my antennas are respectable enough for me to try to radiate more than what my transceivers natively provide. The idea of pushing a kilowatt through a compromise antenna makes me shudder.
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Good to see you back. Hope you post often.
Thanks!
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
Been a ham for 52 years and hold extra class. Licensed since 1969 and still loving it! Mostly HF bands these days, voice, digital and CW buff. Although back in the day I used to enjoy 45 WPM but more recently only about 25 to 30 wpm. Still great fun!
2nd Wind and his XYL on here are good friends of mine too. Just in thought I would chime in and say Hello to all!
Dave - WB8YSQ
I'm what's know as an equipment operator.... properly engineering a station would have been an overwhelming task. Fortunately there is a long tradition of "Elmering" new comers. WB8YSQ is one of our Elmers . Check out his web sight to get an idea how comfortable he is with technology
(PS: Yes, if you had several such archives recorded from different locations, it's possible that you could DF (direction-find: locate geographically) a transmitter from the past.)
At one time, the government was using a highly modified VTR to record the entire HF spectrum, 24/7.
Yes, you could do what you've said. But what the government actually does is a little different. If you have many RF signals to work with, you can use the interference patterns of the signals to deduce the position of reflective objects. When the ionosphere is working, this is an over the horizon radar. The Russians did something similar with a spread spectrum transmitter, the notorious Russian Woodpecker, which blocked entire bands at once. The Chinese are now running a similar system that is a problem for hams in the Pacific region. The US system is more sophisticated, relying on shortwave broadcast, ham signals, etc. When a ham transmits, within about 100 msec the signal is acquired and correlated into the system. An early experimenter shocked the military by using LORAN signals to roughly image aircraft parked at McLellan AFB.
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Hmm...now I'm wondering how hard it would be to hack the firmware.
In some cases, not hard. Years ago, when the FCC was restricting ham linear amplifiers with 10 meter capability, linear amplifier instruction manuals contained a warning not to cut the green wire as shown in Figure 14, lest the amplifier become capable (horrors!) of transmitting high power on 10 meters. In some transceivers it was a matter of removing one surface mounted diode. For full SDR equipment, you could seek out the MARS modifications, which will open up the transmitter.
(PS: Yes, if you had several such archives recorded from different locations, it's possible that you could DF (direction-find: locate geographically) a transmitter from the past.)
At one time, the government was using a highly modified VTR to record the entire HF spectrum, 24/7.
Yes, you could do what you've said. But what the government actually does is a little different. If you have many RF signals to work with, you can use the interference patterns of the signals to deduce the position of reflective objects. When the ionosphere is working, this is an over the horizon radar. The Russians did something similar with a spread spectrum transmitter, the notorious Russian Woodpecker, which blocked entire bands at once. The Chinese are now running a similar system that is a problem for hams in the Pacific region. The US system is more sophisticated, relying on shortwave broadcast, ham signals, etc. When a ham transmits, within about 100 msec the signal is acquired and correlated into the system. An early experimenter shocked the military by using LORAN signals to roughly image aircraft parked at McLellan AFB.
That sounds like a fascinating story. Is there a detailed account of it anywhere that I could read?
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In some cases, not hard. Years ago, when the FCC was restricting ham linear amplifiers with 10 meter capability, linear amplifier instruction manuals contained a warning not to cut the green wire as shown in Figure 14, lest the amplifier become capable (horrors!) of transmitting high power on 10 meters. In some transceivers it was a matter of removing one surface mounted diode. For full SDR equipment, you could seek out the MARS modifications, which will open up the transmitter.
Reminds me of the "raisin bricks" that were sold during Prohibition with the careful warning to the purchaser against following the instructions below, lest he accidentally produce an illegal alcoholic beverage.
Sure, I'm aware of the MARS modifications, but I was thinking of hacking the _firmware,_ not the hardware. There are also a few other things I'd like my radio to do, and I've programmed microcontrollers before. Professionally, even. The source code is helpful, though, if you're making changes that are bigger than trivial, and I suspect A) the source code is not easily available, and B) neither are the automated tests. .
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
This is our current main radio. I can watch 4 different bands at the same time
This is an auto tuning amplifier. I "let" my wife "talk me into" spending a bunch of money on an auto tune amp because I have a gimpy back and moving around to manually tune an amp was not fun... I have Ham buddies who started threating to steal her away after they heard she told me to get the more expensive version
Recently this became a very expensive paper weight when the back up battery that saves the tuning solutions died. It was only a 7 dollar part but was out of stock everywhere I looked. Thanks again to Dave for finding a supplier and soldering it into place with neither of us getting electrocuted in the process (that's a real thing that can happen even when unplugged).
We also got the Flex Maestro so we can run the radio wirelessly
but I was thinking of hacking the _firmware,_ not the hardware.
If I understand correctly, for modern SDR equipment the MARS mods consists of new firmware.
For both my main HF radio and my backup, it's adding a jumper between a pair of adjacent contacts, and then doing a hard system reset. But I have little to no experience with other HF radios, and certainly none inside them.
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
I’m not trying to hi Jack you tread, but are any of you guys interested in old ham radio stuff?
denton is, evidently...
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
Barak, if I was a computer guy I'd sell my Flex in a heart beat and buy an one of these. Open source software big user group that keeps putting out free upgrades. Amazing performance and less money than Flex.
I've been trying to convince WB8YSQ that he needs to buy one of these so I can learn to use it (seriously Dave you know you want to).
Whelenman, restoring older radios (boat anchors) has a cult like following especially among older Hams. If you find a Ham club near you there will be Hams into restoring and operating older gear.
You hustling son of a gun! You have a Flex, of all things. Sheesh.
My shack and my antenna farm--to use completely undeserved terms--are nowhere near worthy of a Flex radio yet, and even if they were, the radios themselves would be out of my reach.
Is Flex doing anything with VHF/UHF yet? If iCOM can do direct sampling up there with their IC-9700, I imagine Flex can come up with a far more expensive way to do the same thing.
Speaking of which, does anybody here have experience with the iCOM IC-9700? I'm curious about it.
"But whether the Constitution really be one thing, or another, this much is certain--that it has either authorized such a government as we have had, or has been powerless to prevent it. In either case, it is unfit to exist." --Lysander Spooner, 1867
