KD0ZGW
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« on: April 13, 2014, 06:34:09 AM » |
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FT840 with g5rv at 40'
I've had several occasions when a seemingly strong signal couldn't be tuned so I could understand it. sound was like I was off freq. but tuning above and below to loss of signal didn't clear it up. Receiver was on correct sideband.
has happened on 20 and 10m and maybe others.
suggestions?
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KG6AF
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« Reply #1 on: April 13, 2014, 08:40:13 AM » |
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FT840 with g5rv at 40'
I've had several occasions when a seemingly strong signal couldn't be tuned so I could understand it. sound was like I was off freq. but tuning above and below to loss of signal didn't clear it up. Receiver was on correct sideband.
has happened on 20 and 10m and maybe others.
suggestions?
The person transmitting might not be using the "correct" sideband. |
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« Last Edit: April 13, 2014, 08:44:29 AM by KG6AF »
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KD0ZGW
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« Reply #2 on: April 13, 2014, 10:11:26 AM » |
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Not wrong sideband; I check that when I am trying to tune those signals.
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K5TED
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« Reply #3 on: April 13, 2014, 11:52:49 AM » |
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What frequencies are you trying to tune? Are they in the amateur bands or outside, on utility segments? There is a fair amount of SSB traffic on the utility bands that are using either inverted or otherwise scrambled SSB.
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KD0ZGW
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Posts: 483
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« Reply #4 on: April 13, 2014, 01:33:36 PM » |
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signals are in the ham bands.
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RENTON481
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« Reply #5 on: April 14, 2014, 09:10:29 PM » |
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Maybe you have something either switched on that needs to be switched off, or vice versa?
Maybe an AGC setting needs to be adjusted (if there is one on the Yaesu radio)?
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N1DVJ
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« Reply #6 on: April 15, 2014, 07:44:52 AM » |
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With a strong signal, could it be that you are actually listening to the supressed sideband upside down? Like listening to the wrong sideband on a DSBSC signal.
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W8MW
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« Reply #7 on: April 16, 2014, 06:14:54 PM » |
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Based on the info you've provided it sounds like you are listening to the opposite sideband. If it happens again, switch sidebands, re-tune and see if that doesn't clear up the issue. An experiment you might try is tune into a SSB signal that you are receiving correctly. Then switch sideband and re-tune the signal. If you get the same unintelligible result you have confirmed the original issue.
73 Mike W8MW
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KF7CG
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« Reply #8 on: April 17, 2014, 01:56:31 PM » |
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Could also be hunters or others that are using "export" radios for communication. They often do not know, care, or want to know the coventions of where they operate. A frequency setting and sideband setting is chosen for the day and used. They are looking for privacy and anything that makes them unintelligible to anyone other than their group is a plus.
So by all means check the other sideband when you hear one, no telling what you will find.
KF7CG
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K8KAS
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« Reply #9 on: April 18, 2014, 05:19:57 AM » |
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Simple front end over load, the 840 is not known for it dynamic range, that's why they provide you padding to lower the front end signal level, lot of radios do this...73 Denny K8KAS
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KB8VIV
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« Reply #10 on: April 18, 2014, 06:11:44 AM » |
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+1 Simple front end over load, the 840 is not known for it dynamic range, that's why they provide you padding to lower the front end signal level, lot of radios do this...73 Denny K8KAS
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N4UE
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« Reply #11 on: April 20, 2014, 04:38:03 PM » |
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Turn off the Noise Blanker?
ron
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K5BM
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« Reply #12 on: April 22, 2014, 07:08:46 PM » |
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It could be flat topping or the amplifier is biased too close to cutoff(class C).
Tom, k5bm
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K6AER
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« Reply #13 on: May 02, 2014, 07:20:28 PM » |
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One person got close...turn down the RF gain control.
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KD8IIC
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« Reply #14 on: May 11, 2014, 12:39:47 PM » |
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Tnx AER....You're right on the mark with it...I find most every CW and SSB signal can be cleaned up very well by simply cutting back about a quater to a half turn on the RF Gain and turn up the volume to compensate, also the built in attenuators on some rigs will help as well.
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