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#1
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My initial testing on an FT-991 I bought Tuesday indictaes AM
transmission is severely distorted. I tried everything in the manual that seemed relevant to AM transmission without any improvement. Transmitting into a Cobra Senior perfectly matched with a Nye Viking MBII on 3885 showed pronounced downward modulation even on a peak reading MFJ 870 meter. Normally a peak reading watt meter will show strong upward movement as the peak power is 4 times carrier power. I called Yaesu tech support. The tech was not aware of any prolbems with AM on the 991. He suggested I reset the processor. After the processor reset returned the 991 to its factory defaults, the 3885 morning crowd confirmed the transmitted signal was still terrible. I have been able to get good results transmitting AM with many oher radios including IC706mkiiG, 756Pro, and FlexRadio 5000a. A quick check on 2 meters showed the same profound downward modulation on the FT-991. Anyone having better luck with AM on the FT-991? -de WA7KGX |
#2
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In article ,
wa7kgx wrote: My initial testing on an FT-991 I bought Tuesday indictaes AM transmission is severely distorted. I tried everything in the manual that seemed relevant to AM transmission without any improvement. Transmitting into a Cobra Senior perfectly matched with a Nye Viking MBII on 3885 showed pronounced downward modulation even on a peak reading MFJ 870 meter. Normally a peak reading watt meter will show strong upward movement as the peak power is 4 times carrier power. I called Yaesu tech support. The tech was not aware of any prolbems with AM on the 991. He suggested I reset the processor. After the processor reset returned the 991 to its factory defaults, the 3885 morning crowd confirmed the transmitted signal was still terrible. I have been able to get good results transmitting AM with many oher radios including IC706mkiiG, 756Pro, and FlexRadio 5000a. A quick check on 2 meters showed the same profound downward modulation on the FT-991. Anyone having better luck with AM on the FT-991? WA7KGX- I have the same problem with my FT-991, with the Po Meter kicking downward with modulation. The manual’s procedure for setting AM Microphone gain does not work. They instruct you to adjust so ALC does not deflect when speaking. If you do that, there is no modulation. The ALC meter has a static level that kicks upward with modulation. It might help if we compared notes on other problems. From what I can tell, both the hardware and firmware have bugs. Here are some other problems I've found: 1. On several occasions the radio has locked-up, stopped receiving or refused to transmit. Recycling power cleared up the problem. 2. On 14, 50 and 430 MHz SSB, the ALC Meter reading is missing, depending on antenna SWR. On 14 and 50 it only works if SWR is high, on 430 if it is low. 3. If you look at the left side of the display, you may see IPO, AMP1 or AMP2 listed. It depends on the IPO setting on HF. AMP1 and AMP2 do not apply to VHF or UHF. They may appear there as well, and can only be changed by re-programming the frequency. If you select an HF frequency in VFO mode, you can turn the AMPs on and off. Whatever state they are in, remains if you then select BAND - ENT and enter a VHF or UHF frequency. 4. The 5/10 Hz setting is stuck on 5 Hz for AM, FM, C4FM and DATA-FM modes. Main-dial frequency step is 100Hz, but CLARifier is 5 Hz. 5. In order to use a program like CHIRP to program the radio, it is necessary to start up the radio in Clone mode The manual is missing information on CAT and Cloning. FT-817/857/897 Clone setup does not work with the FT-991, which is missing the two Mode buttons. I would be interested in knowing if you have observed any of these problems in your FT-991. Fred K4DII |
#3
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On Mon, 02 Feb 2015 18:34:02 -0500, Fred McKenzie wrote:
In article , wa7kgx wrote: My initial testing on an FT-991 I bought Tuesday indictaes AM transmission is severely distorted. I tried everything in the manual that seemed relevant to AM transmission without any improvement. Transmitting into a Cobra Senior perfectly matched with a Nye Viking MBII on 3885 showed pronounced downward modulation even on a peak reading MFJ 870 meter. Normally a peak reading watt meter will show strong upward movement as the peak power is 4 times carrier power. I called Yaesu tech support. The tech was not aware of any prolbems with AM on the 991. He suggested I reset the processor. After the processor reset returned the 991 to its factory defaults, the 3885 morning crowd confirmed the transmitted signal was still terrible. I have been able to get good results transmitting AM with many oher radios including IC706mkiiG, 756Pro, and FlexRadio 5000a. A quick check on 2 meters showed the same profound downward modulation on the FT-991. Anyone having better luck with AM on the FT-991? WA7KGX- I have the same problem with my FT-991, with the Po Meter kicking downward with modulation. The manual’s procedure for setting AM Microphone gain does not work. They instruct you to adjust so ALC does not deflect when speaking. If you do that, there is no modulation. The ALC meter has a static level that kicks upward with modulation. It might help if we compared notes on other problems. From what I can tell, both the hardware and firmware have bugs. Here are some other problems I've found: 1. On several occasions the radio has locked-up, stopped receiving or refused to transmit. Recycling power cleared up the problem. 2. On 14, 50 and 430 MHz SSB, the ALC Meter reading is missing, depending on antenna SWR. On 14 and 50 it only works if SWR is high, on 430 if it is low. 3. If you look at the left side of the display, you may see IPO, AMP1 or AMP2 listed. It depends on the IPO setting on HF. AMP1 and AMP2 do not apply to VHF or UHF. They may appear there as well, and can only be changed by re-programming the frequency. If you select an HF frequency in VFO mode, you can turn the AMPs on and off. Whatever state they are in, remains if you then select BAND - ENT and enter a VHF or UHF frequency. 4. The 5/10 Hz setting is stuck on 5 Hz for AM, FM, C4FM and DATA-FM modes. Main-dial frequency step is 100Hz, but CLARifier is 5 Hz. 5. In order to use a program like CHIRP to program the radio, it is necessary to start up the radio in Clone mode The manual is missing information on CAT and Cloning. FT-817/857/897 Clone setup does not work with the FT-991, which is missing the two Mode buttons. I would be interested in knowing if you have observed any of these problems in your FT-991. Fred K4DII Based on previous experience reviewing the Yaesu Spirit ham/aviation handheld for Aviation Consumer and W7WAA's commenta on the Yaesu FTDX-1200, I decided not to wait for a miracle to happen soon at Yaesu and took the FT-991 back to HRO and insisted on getting my money back. The radio does not meet its advertised description. |
#4
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The air checks are available at http:www.omen.com/waykgx/ham.html
For some reason I couldn't post the sound files to the newsgroup with PAN. |
#5
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In article ,
wa7kgx wrote: The air checks are available at http:www.omen.com/waykgx/ham.html For some reason I couldn't post the sound files to the newsgroup with PAN. WA7KGX- Some news servers do not accept files. I saw your comments on the eHam net forum. I have a list of several problems with my FT-991, including the defective AM. There are some things I like about the radio, so I prefer to get it repaired rather than getting a refund. The reason AM power is set to 25 Watts, is that the radio is only capable of 100 Watts. One hundred Watts is the peak power of a 100 percent modulated 25 Watt AM signal. The FT-991 Po meter should kick from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward instead. If you can not get a refund, I suggest you also take the "repair" approach. There is no reason the radio should not produce an acceptable AM signal. It almost certainly is misaligned, and can be corrected. If Yaesu can not correct the problem by alignment, then they should replace the defective module. With regard to your other comment about listening to a repeater's input frequency, you can easily do that with the REV function. You will notice that it changes the memory contents, so you must press the REV a second time to return to normal frequencies. That is one of my minor gripes about the radio, that some functions directly affect memory, rather than a "working copy" of the memory. 73, Fred K4DII |
#6
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On Fri, 13 Feb 2015 01:30:16 -0500, Fred McKenzie wrote:
In article , wa7kgx wrote: The air checks are available at http:www.omen.com/waykgx/ham.html For some reason I couldn't post the sound files to the newsgroup with PAN. WA7KGX- Some news servers do not accept files. I saw your comments on the eHam net forum. I have a list of several problems with my FT-991, including the defective AM. There are some things I like about the radio, so I prefer to get it repaired rather than getting a refund. The reason AM power is set to 25 Watts, is that the radio is only capable of 100 Watts. One hundred Watts is the peak power of a 100 percent modulated 25 Watt AM signal. The FT-991 Po meter should kick from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward instead. If you can not get a refund, I suggest you also take the "repair" approach. There is no reason the radio should not produce an acceptable AM signal. It almost certainly is misaligned, and can be corrected. If Yaesu can not correct the problem by alignment, then they should replace the defective module. With regard to your other comment about listening to a repeater's input frequency, you can easily do that with the REV function. You will notice that it changes the memory contents, so you must press the REV a second time to return to normal frequencies. That is one of my minor gripes about the radio, that some functions directly affect memory, rather than a "working copy" of the memory. 73, Fred K4DII First time I tried using REV: set fm repeater 145.29 rpt - offset. REV made a sound but did nothing. Did a full processor reset, same result. Then on a hunch I set repeater offset to + and voila! REV works. This is one buggy radio. |
#7
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On Fri, 13 Feb 2015 02:30:57 -0600, wa7kgx wrote:
On Fri, 13 Feb 2015 01:30:16 -0500, Fred McKenzie wrote: In article , wa7kgx wrote: The air checks are available at http:www.omen.com/waykgx/ham.html For some reason I couldn't post the sound files to the newsgroup with PAN. WA7KGX- Some news servers do not accept files. I saw your comments on the eHam net forum. I have a list of several problems with my FT-991, including the defective AM. There are some things I like about the radio, so I prefer to get it repaired rather than getting a refund. The reason AM power is set to 25 Watts, is that the radio is only capable of 100 Watts. One hundred Watts is the peak power of a 100 percent modulated 25 Watt AM signal. The FT-991 Po meter should kick from 25 Watts to nearly 100 watts on voice peaks. Mine kicks downward instead. If you can not get a refund, I suggest you also take the "repair" approach. There is no reason the radio should not produce an acceptable AM signal. It almost certainly is misaligned, and can be corrected. If Yaesu can not correct the problem by alignment, then they should replace the defective module. With regard to your other comment about listening to a repeater's input frequency, you can easily do that with the REV function. You will notice that it changes the memory contents, so you must press the REV a second time to return to normal frequencies. That is one of my minor gripes about the radio, that some functions directly affect memory, rather than a "working copy" of the memory. 73, Fred K4DII First time I tried using REV: set fm repeater 145.29 rpt - offset. REV made a sound but did nothing. Did a full processor reset, same result. Then on a hunch I set repeater offset to + and voila! REV works. This is one buggy radio. Yaesu have posted firmware updates to the FT-991 as well as the CAT codes. |
#8
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In article ,
wa7kgx wrote: Yaesu have posted firmware updates to the FT-991 as well as the CAT codes. I updated my FT-991 yesterday and spent most of today re-entering channel data lost in the reset. There are two separate updates, one called "Main" and one called "DSP". Each has its own updater program. The Main update went smoothly but the DSP updater needed some help. It seems that Yaesu's "enhanced" USB driver installed as COM14 on my computer, but the DSP updater can only handle COM ports 1 through 10. It took some research to learn how to change COM14 to COM1. After making that change, the DSP update went smoothly. I do not know what all was changed, but did notice that the AM mode is working differently. Instead of kicking downward during modulation, the Po meter barely wiggles. It does kick downward slightly with the microphone gain turned up high. I hear some distortion on a local receiver, but it may be due to overload. Looking at a PEP wattmeter, I would guess that modulation percentage might be around 70 or 80 percent. A scope might tell a different story. 73, Fred K4DII |
#9
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On Friday, February 27, 2015 at 7:09:51 PM UTC-5, Fred McKenzie wrote:
In article , wa7kgx wrote: Yaesu have posted firmware updates to the FT-991 as well as the CAT codes. I updated my FT-991 yesterday and spent most of today re-entering channel data lost in the reset. There are two separate updates, one called "Main" and one called "DSP". Each has its own updater program. The Main update went smoothly but the DSP updater needed some help. It seems that Yaesu's "enhanced" USB driver installed as COM14 on my computer, but the DSP updater can only handle COM ports 1 through 10. It took some research to learn how to change COM14 to COM1. After making that change, the DSP update went smoothly. I do not know what all was changed, but did notice that the AM mode is working differently. Instead of kicking downward during modulation, the Po meter barely wiggles. It does kick downward slightly with the microphone gain turned up high. I hear some distortion on a local receiver, but it may be due to overload. Looking at a PEP wattmeter, I would guess that modulation percentage might be around 70 or 80 percent. A scope might tell a different story. 73, Fred K4DII hey dave on am do you know what the power output should be mine only does 20 watts on am |
#10
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If the 991 is like other Yaesu rigs, you will need to inject a voltage into the ALC port on the back using a battery and a pot. See W8JI's excellent page on this very topic at http://www.w8ji.com/amplitude_modulation.htm
You may also have to set the carrier in that mode using a menu item in a manner simlilarly as the 897. It seems a LOT of solid state rigs do this (ie downward modulate). GOTO to the Foxtango Group on Yahoo for more inflammation. Philip KA4KOE |
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