Re: [Flexradio] auto tuners and limits thereof
On Mon, Mar 15, 2010 at 7:24 AM, Gerald Youngblood wrote: > The FLEX-5000 ATU is a turnkey OEM module from LDG, including the ATU > firmware. The FLEX-3000 is a FlexRadio design. We are completing > significant improvements to the FLEX-3000 ATU firmware that will soon be > ported to the FLEX-5000 ATU, which can be completely controlled over its > communications port. That answers why I have a block diagram and no schematic. That's also what I get for speculating. :-) Thanks Gerald. -- 73 de Brian, WB6RQN/J79BPL ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] auto tuners and limits thereof
The FLEX-5000 ATU is a turnkey OEM module from LDG, including the ATU firmware. The FLEX-3000 is a FlexRadio design. We are completing significant improvements to the FLEX-3000 ATU firmware that will soon be ported to the FLEX-5000 ATU, which can be completely controlled over its communications port. Regards, Gerald Gerald Youngblood, K5SDR President and CEO FlexRadio Systems(TM) 13091 Pond Springs Road, #250 Austin, TX 78729 Phone: 512-535-4713 Ext. 202 Email: ger...@flex-radio.com Web: www.flex-radio.com Tune In Excitement (TM) PowerSDR(TM) is a trademark of FlexRadio Systems On Sun, Mar 14, 2010 at 8:18 PM, Brian Lloyd wrote: > 2010/3/14 Alan NV8A : > > Am I correct in thinking that the FLEX-5000A ATU is in fact a custom > version > > of one of the LDG or SGC tuners? How well does the "original" work with a > > similarly mismatched antenna? > > You would have to as Flex but here is my > worth-everything-you-paid-for-it take on this. > > Well, it is definitely different from my SGC-231 and the other SGC > schematics I have seen. I can't answer for LDG. Regardless, an ATU is > a well-understood thing. It is probably just as easy to start from > scratch. > > Consider that the firmware for the SGC and LDG tuners works peachy but > that the firmware in the Flex tuners still need "tuning". That implies > to me that it is a separate design. Why purchase the rights to the > hardware (the easy part) and not also purchase the rights to the > firmware (the hard part). > > -- > 73 de Brian, WB6RQN/J79BPL > > ___ > FlexRadio Systems Mailing List > FlexRadio@flex-radio.biz > http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz > Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ > Knowledge Base: http://kc.flex-radio.com/ Homepage: > http://www.flex-radio.com/ > ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] auto tuners and limits thereof
2010/3/14 Alan NV8A : > Am I correct in thinking that the FLEX-5000A ATU is in fact a custom version > of one of the LDG or SGC tuners? How well does the "original" work with a > similarly mismatched antenna? You would have to as Flex but here is my worth-everything-you-paid-for-it take on this. Well, it is definitely different from my SGC-231 and the other SGC schematics I have seen. I can't answer for LDG. Regardless, an ATU is a well-understood thing. It is probably just as easy to start from scratch. Consider that the firmware for the SGC and LDG tuners works peachy but that the firmware in the Flex tuners still need "tuning". That implies to me that it is a separate design. Why purchase the rights to the hardware (the easy part) and not also purchase the rights to the firmware (the hard part). -- 73 de Brian, WB6RQN/J79BPL ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] auto tuners and limits thereof
On 03/14/10 06:58 pm, Brian Lloyd wrote: 2. Flex advertises their Flex 5000 ATU to work with a 10:1 SWR. This is false advertising as the Flex ATU struggles with 2:1 SWRs. 10:1 SWR would be a wet noodle antenna. It actually *will* match a 10:1 mismatch. Try connecting a 500Ω or a 5Ω load and it will match it. But that is not the real story. A "tuner" actually does two things: 1. "tunes out" (cancels) whatever reactance is present; 2. provides an impedance transformation from whatever is at the input to 50 ohms. For most tuners, the available reactive and resistive ranges are interdependent. The more reactive the antenna, the more limited the tuner is in matching the resistive component. It would be much better if tuners were spec'd by the reactance and resistance ranges that they will tune. Sounds like something the ARRL might do in their labs. As for tuning a "wet noodle," an end-fed 1/2 wave antenna has an impedance of about 8000Ω or an SWR of about 160:1. There are precious few tuners that can handle that mismatch. That might actually be worse than a "wet noodle." :-) 3. On bands like 75, 15, and 10 mtrs, an antenna will not have a low SWR over the whole band. An internal antenna will "help" the radio work the whole band. It depends on the 'Q' of the antenna. It is common to increase the bandwidth of a monopole by increasing its diameter or by switching to a folded monopole so that a tuner isn't required over the whole band. 5. Every internal tuner I have had in a radio works on 3:1 SWRs. My last radio, the Icom Pro III worked perfectly with my antennas. The Flex ATU does not. I do not expect the Flex ATU to load up a wet noodle. I DO expect it to work as well as other internal tuners. Well, Gerald did say they were aware of the limitations and that they are improving the code. So far, other than the time it takes to get things done, Flex has been very good about keeping its promises. Getting back to my original comment about comparing tuners, it would be nice to know what the inductance and capacitance ranges are so that it can be compared to other tuners. If you look at the block diagram you will see that it is an 'L' network but that the shunt capacitance can be switched to either side of the series inductance. Knowing the minimum and maximum inductance and capacitance will tell you what the matching range is. Am I correct in thinking that the FLEX-5000A ATU is in fact a custom version of one of the LDG or SGC tuners? How well does the "original" work with a similarly mismatched antenna? 73 Alan NV8A ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] auto tuners and limits thereof
On Sun, Mar 14, 2010 at 11:53 AM, Lazy Senior wrote: > 2. Flex advertises their Flex 5000 ATU to work with a 10:1 SWR. This is > false advertising as the Flex ATU struggles with 2:1 SWRs. 10:1 SWR would be > a wet noodle antenna. It actually *will* match a 10:1 mismatch. Try connecting a 500Ω or a 5Ω load and it will match it. But that is not the real story. A "tuner" actually does two things: 1. "tunes out" (cancels) whatever reactance is present; 2. provides an impedance transformation from whatever is at the input to 50 ohms. For most tuners, the available reactive and resistive ranges are interdependent. The more reactive the antenna, the more limited the tuner is in matching the resistive component. It would be much better if tuners were spec'd by the reactance and resistance ranges that they will tune. Sounds like something the ARRL might do in their labs. As for tuning a "wet noodle," an end-fed 1/2 wave antenna has an impedance of about 8000Ω or an SWR of about 160:1. There are precious few tuners that can handle that mismatch. That might actually be worse than a "wet noodle." :-) > 3. On bands like 75, 15, and 10 mtrs, an antenna will not have a low SWR > over the whole band. An internal antenna will "help" the radio work the > whole band. It depends on the 'Q' of the antenna. It is common to increase the bandwidth of a monopole by increasing its diameter or by switching to a folded monopole so that a tuner isn't required over the whole band. > 5. Every internal tuner I have had in a radio works on 3:1 SWRs. My last > radio, the Icom Pro III worked perfectly with my antennas. The Flex ATU does > not. I do not expect the Flex ATU to load up a wet noodle. I DO expect it to > work as well as other internal tuners. Well, Gerald did say they were aware of the limitations and that they are improving the code. So far, other than the time it takes to get things done, Flex has been very good about keeping its promises. Getting back to my original comment about comparing tuners, it would be nice to know what the inductance and capacitance ranges are so that it can be compared to other tuners. If you look at the block diagram you will see that it is an 'L' network but that the shunt capacitance can be switched to either side of the series inductance. Knowing the minimum and maximum inductance and capacitance will tell you what the matching range is. -- 73 de Brian, WB6RQN/J79BPL ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
Re: [Flexradio] auto tuners and limits thereof
There are several problems here. 1. SWR has NO relationship to how well an antenna works or radiates. A REAL antenna does not need a low SWR. Please obtain a copy of Maxwells Reflections and learn something about SWR and the Myths many hams believe. 2. Flex advertises their Flex 5000 ATU to work with a 10:1 SWR. This is false advertising as the Flex ATU struggles with 2:1 SWRs. 10:1 SWR would be a wet noodle antenna. 3. On bands like 75, 15, and 10 mtrs, an antenna will not have a low SWR over the whole band. An internal antenna will "help" the radio work the whole band. 4. Most radios - including the Flex folds back power the higher the SWR. Internal tuners help protect the radio. 5. Every internal tuner I have had in a radio works on 3:1 SWRs. My last radio, the Icom Pro III worked perfectly with my antennas. The Flex ATU does not. I do not expect the Flex ATU to load up a wet noodle. I DO expect it to work as well as other internal tuners. 6. The MFJ 993B is an excellent example of an auto tuner that works the way it should. Stan K9IUQ Carl N9GC wrote: Their basic philosophy is that the tuner works with loads with SWR of less than 3 to 1. They make no apologies for this "limit" but say very candidly that if you have an SWR of over 3 to 1 that you have an antenna problem, not a tuner or radio problem, and they suggest that you fix your antenna problem! Or to put it less politely than they did (what follows are my words), Please don't expect this expensive world class contest grade transceiver to load up your wet piece of string that's at 15 feet height next to aluminum gutters. If you want a real station, you have half of it, a good transceiver. Now get a real antenna. I have been using the MFJ 993B auto tuner for a year and it works very well with my very poor antenna setup in an attic. When it won't match what I have, I know I am once again trying to violate (not break) the laws of physics. Rant meter now off. 73, Carl N9GC ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/ ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
[Flexradio] auto tuners and limits thereof
Having owned an SDR1000 (sans tuner) and a Yaesu FT1000MP MkV, I became familiar with the good and bad points of the internal tuner of the MkV. The manual has a very good discussion of what to expect from an internal tuner. Or, as I like to say, finally someone had the guts to put it in print. Their basic philosophy is that the tuner works with loads with SWR of less than 3 to 1. They make no apologies for this "limit" but say very candidly that if you have an SWR of over 3 to 1 that you have an antenna problem, not a tuner or radio problem, and they suggest that you fix your antenna problem! Or to put it less politely than they did (what follows are my words), Please don't expect this expensive world class contest grade transceiver to load up your wet piece of string that's at 15 feet height next to aluminum gutters. If you want a real station, you have half of it, a good transceiver. Now get a real antenna. I have been using the MFJ 993B auto tuner for a year and it works very well with my very poor antenna setup in an attic. When it won't match what I have, I know I am once again trying to violate (not break) the laws of physics. Rant meter now off. 73, Carl N9GC ___ FlexRadio Systems Mailing List FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kc.flex-radio.com/ Homepage: http://www.flex-radio.com/
