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Wouxun KG 1000G Modulation problem


lakemen

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Just wondering if I should be contacting "bytwowayradios.com"...???
 
Ben
WRAX296

It is worth the call to see what they have to say, particularly if radio is new.

I have done some experiments on my end and currently learning towards an internally maladjusted AGC circuit in the outbound audio path. Initial audio levels seems good when first transmitting but it includes gross audio clipping (distortion), then the audio drops down to almost nothing and then ramps back up to ‘normal’, but includes some degree of clipping. In my over-the-air experiments with some seasoned operators it has been reported that the problem seems to mostly go away when the mic is held 6-10 inches away from the mouth. This is not generally good in a mobile situation. However, if get acceptable results at this distance, I may modify the mic my mic to pad its audio down so that I can use the mic closer to the mouth to cut down on the background noise.

One local swears he has read some posts overseas about folks reporting this same problem, but while using the KG-UV980 (same electronics as the KG-1000G). Reportedly at least one of them managed to get their hands on some kind of service software package which had allowed them to disable that circuit and that it solved their problem. I have looked far and wide with no luck, so I suspect he may be thinking of a different radio model. In any regards, he promised to try and find the original thread and send me a link. We will see. I will keep you in mind if such software is actually found.


Michael
WRHS965
KE8PLM
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On 12/30/2021 at 7:19 AM, mbrun said:


It is worth the call to see what they have to say, particularly if radio is new.

I have done some experiments on my end and currently learning towards an internally maladjusted AGC circuit in the outbound audio path. Initial audio levels seems good when first transmitting but it includes gross audio clipping (distortion), then the audio drops down to almost nothing and then ramps back up to ‘normal’, but includes some degree of clipping. In my over-the-air experiments with some seasoned operators it has been reported that the problem seems to mostly go away when the mic is held 6-10 inches away from the mouth. This is not generally good in a mobile situation. However, if get acceptable results at this distance, I may modify the mic my mic to pad its audio down so that I can use the mic closer to the mouth to cut down on the background noise.

One local swears he has read some posts overseas about folks reporting this same problem, but while using the KG-UV980 (same electronics as the KG-1000G). Reportedly at least one of them managed to get their hands on some kind of service software package which had allowed them to disable that circuit and that it solved their problem. I have looked far and wide with no luck, so I suspect he may be thinking of a different radio model. In any regards, he promised to try and find the original thread and send me a link. We will see. I will keep you in mind if such software is actually found.


Michael
WRHS965
KE8PLM

 

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I realize this thread is pretty old, but has anyone found a solution to this problem? 

Everyone I know with a KG-1000G has the same audio rollercoaster problem. It starts out loud, ramps down, then back up within seconds. It's really irritating and there seems to be no way to fix it in the settings (nor with multiple returns under warranty). 

For a radio priced like a Yaesu, this thing has been disappointing. Also, the fan sounds like a Vitamix full of ice. 

I could get past its other issues if my audio didn't have this ramp up, down, up problem. 

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I have found a particular issue with this radio.  It seems if you leave the lower channels with high power programmed in memory, the radio will automatically switch to low to be FCC compliant.   The time it takes the radio to automatically switch to low power is the cause of the delayed audio output on transmit.  It seems to affect other channels if left with high power programming in the lower channels.   Once again poor firmware problems.  

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The audio problem is caused by the Automatic Gain Control (AGC) being a bit aggressive.  Everyone I know that has this issue is able to improve it by not holding the mic so close to their mouth and holding it at a slight angle from their mouth (instead of directly in front of their mouth) so they aren't "popping" their Ps and Ts.

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I have found a particular issue with this radio.  It seems if you leave the lower channels with high power programmed in memory, the radio will automatically switch to low to be FCC compliant.   The time it takes the radio to automatically switch to low power is the cause of the delayed audio output on transmit.  It seems to affect other channels if left with high power programming in the lower channels.   Once again poor firmware problems.

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I have found a particular issue with this radio.  It seems if you leave the lower channels with high power programmed in memory, the radio will automatically switch to low to be FCC compliant.   The time it takes the radio to automatically switch to low power is the cause of the delayed audio output on transmit.  It seems to affect other channels if left with high power programming in the lower channels.   Once again poor firmware problems.

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39 minutes ago, StepUp2TheMyke said:

The time it takes the radio to automatically switch to low power is the cause of the delayed audio output on transmit.

This is not the case with any of the radios I've dealt with having the audio issue discussed in this thread.  FYI: posting the same incorrect information multiple times wont make the information any less wrong.

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In a related question, does anyone know whether or not the KG-1000G PLUS has the same issue?

Also, the specifications in the manual for the KG-1000G says that Wideband deviation is +/- 5KHZ and Narrowband is +/- 2.5KHz. In the past commercial and amateur radio WB was always +/- 12.5 KHz and NB was +/- 5KHz. The +/- 2.5 KHz is used on the FRZ interstitial channels. Our GMRS club repeaters are commercial radios and are limited to +/- 5 KHz, which is considered NB. If a user's KG-1000 G radio is set to NB, the audio would be low on a NB repeater like ours.

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1 hour ago, WRNA710AZ said:

In a related question, does anyone know whether or not the KG-1000G PLUS has the same issue?

Also, the specifications in the manual for the KG-1000G says that Wideband deviation is +/- 5KHZ and Narrowband is +/- 2.5KHz. In the past commercial and amateur radio WB was always +/- 12.5 KHz and NB was +/- 5KHz. The +/- 2.5 KHz is used on the FRZ interstitial channels. Our GMRS club repeaters are commercial radios and are limited to +/- 5 KHz, which is considered NB. If a user's KG-1000 G radio is set to NB, the audio would be low on a NB repeater like ours.

Don’t confuse bandwidth with deviation (if I understand you correctly).

The two things are addressed separately in regulations:

§ 95.1773 GMRS authorized bandwidths.

Each GMRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the channels used. Operation of GMRS stations must also be in compliance with these requirements. 

(a) Main channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz main channels (see § 95.1763(a)) or any of the 467 MHz main channels (see § 95.1763(c)). 

(b) Interstitial channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz interstitial channels (see § 95.1763(b)) and is 12.5 kHz for GMRS transmitters operating on any of the 467 MHz interstitial channels (see § 95.1763(d)). 

(c) Digital data transmissions. Digital data transmissions are limited to the 462 MHz main channels and interstitial channels in the 462 MHz and 467 MHz bands. 

§ 95.1775 GMRS modulation requirements.

Each GMRS transmitter type must be designed to satisfy the modulation requirements in this section. Operation of GMRS stations must also be in compliance with these requirements. 

(a) Main channels. The peak frequency deviation for emissions to be transmitted on the main channels must not exceed ± 5 kHz. 

(b) 462 MHz interstitial channels. The peak frequency deviation for emissions to be transmitted on the 462 MHz interstitial channels must not exceed ± 5 kHz. 

(c) 467 MHz interstitial channels. The peak frequency deviation for emissions to be transmitted on the 467 MHz interstitial channels must not exceed ± 2.5 kHz, and the highest audio frequency contributing substantially to modulation must not exceed 3.125 kHz. 

(d) Overmodulation. Each GMRS transmitter type, except for a mobile station transmitter type with a transmitter power output of 2.5 W or less, must automatically prevent a higher than normal audio level from causing overmodulation. 

(e) Audio filter. Each GMRS transmitter type must include audio frequency low pass filtering, unless it complies with the applicable paragraphs of § 95.1779 (without filtering). 

(1) The filter must be between the modulation limiter and the modulated stage of the transmitter. 

(2) At any frequency (f in kHz) between 3 and 20 kHz, the filter must have an attenuation of at least 60 log (f/3) dB more than the attenuation at 1 kHz. Above 20 kHz, it must have an attenuation of at least 50 dB more than the attenuation at 1 kHz.

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11 minutes ago, Sshannon said:

Don’t confuse bandwidth with deviation (if I understand you correctly).

The two things are addressed separately in regulations:

§ 95.1773 GMRS authorized bandwidths.

Each GMRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the channels used. Operation of GMRS stations must also be in compliance with these requirements. 

(a) Main channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz main channels (see § 95.1763(a)) or any of the 467 MHz main channels (see § 95.1763(c)). 

(b) Interstitial channels. The authorized bandwidth is 20 kHz for GMRS transmitters operating on any of the 462 MHz interstitial channels (see § 95.1763(b)) and is 12.5 kHz for GMRS transmitters operating on any of the 467 MHz interstitial channels (see § 95.1763(d)). 

(c) Digital data transmissions. Digital data transmissions are limited to the 462 MHz main channels and interstitial channels in the 462 MHz and 467 MHz bands. 

§ 95.1775 GMRS modulation requirements.

Each GMRS transmitter type must be designed to satisfy the modulation requirements in this section. Operation of GMRS stations must also be in compliance with these requirements. 

(a) Main channels. The peak frequency deviation for emissions to be transmitted on the main channels must not exceed ± 5 kHz. 

(b) 462 MHz interstitial channels. The peak frequency deviation for emissions to be transmitted on the 462 MHz interstitial channels must not exceed ± 5 kHz. 

(c) 467 MHz interstitial channels. The peak frequency deviation for emissions to be transmitted on the 467 MHz interstitial channels must not exceed ± 2.5 kHz, and the highest audio frequency contributing substantially to modulation must not exceed 3.125 kHz. 

(d) Overmodulation. Each GMRS transmitter type, except for a mobile station transmitter type with a transmitter power output of 2.5 W or less, must automatically prevent a higher than normal audio level from causing overmodulation. 

(e) Audio filter. Each GMRS transmitter type must include audio frequency low pass filtering, unless it complies with the applicable paragraphs of § 95.1779 (without filtering). 

(1) The filter must be between the modulation limiter and the modulated stage of the transmitter. 

(2) At any frequency (f in kHz) between 3 and 20 kHz, the filter must have an attenuation of at least 60 log (f/3) dB more than the attenuation at 1 kHz. Above 20 kHz, it must have an attenuation of at least 50 dB more than the attenuation at 1 kHz.

If anyone is mixing terms, it's Wouxun. My question is correct as it stands.

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6 hours ago, WRNA710AZ said:

If anyone is mixing terms, it's Wouxun. My question is correct as it stands.

2023-05-11_13-12-00.jpg

2023-05-11_13-13-39.jpg

I think time is catching up to me; time, newer regulations, and new terminology. When I was in radio technology between 1975 and 2001 Wideband was Wideband and Normal the +/- 5KHz. Apparently, what was Normal, is now considered Wideband, and Narrowband is really narrow, and what they use for FRS radios. Now, with the narrowband commercial repeaters, the mobile or portable should be programmed for Wideband for repeater and simplex, unless they are operated on GMRS channels 8 through 14 (the interstitial 0.5watt channels) which should then be programmed for narrowband. I'm going to assume that the majority, if not all radios, have built-in limiting for those frequencies.

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On 5/11/2023 at 11:05 PM, WRNA710AZ said:

I think time is catching up to me; time, newer regulations, and new terminology. When I was in radio technology between 1975 and 2001 Wideband was Wideband and Normal the +/- 5KHz. Apparently, what was Normal, is now considered Wideband, and Narrowband is really narrow, and what they use for FRS radios. Now, with the narrowband commercial repeaters, the mobile or portable should be programmed for Wideband for repeater and simplex, unless they are operated on GMRS channels 8 through 14 (the interstitial 0.5watt channels) which should then be programmed for narrowband. I'm going to assume that the majority, if not all radios, have built-in limiting for those frequencies.

This goes back a few decades -- when the FCC mandated "narrowbanding" for land mobile/business/law-enforcement...

GMRS and Amateur essentially were exempted from "narrowbanding". This is also why you'll find posts about having to find a non-narrowbanded commercial radio if one intends to program it for GMRS.

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