ANYTONE AT-5555N2 receive noise work-around

[unit_399]

Received a new post from DAVID DONALDSON's (91DD018) blog today titled "ANYTONE AT-5555N2 and S5 -7 NOISE."
Evidentally there is a problem with this model and its clones where a S5 to S7 noise level is always present in receive. David has come up with a nice work-around that alleviates the problem somewhat. I have reprinted the post from David's Blog below. I'm certain it will be of interest to many of our members.

NOTE: In the past whenever I reposted one of David's posts, some nitwit from New Zealand always accused me of trying to take credit for David's work. Evidentally this clown can't read, as I always give credit where credit is due. Just putting this out there in advance.

- 399
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91DD018

AnyTone AT-5555N2 and S 5-7 Noise.​

David Donaldson Feb 14 Reports are coming in of noisy receive and S7 S meter readings with no signal on newer Anytone AT-5555N2's and several of the derivatives. It is certainly real. I have it on mine. I have no idea what causes it. Is it a design change, a component issue or a software issue. Fingers crossed it is software and an easy fix. The N2 does have software to install frequencies but I do not know if the same cable with different software can be used for updating the firmware or Service Menu settings in these radios. If it is possible, Anytone are keeping very quiet about it. So far as we are presently aware any changes to the radio's working parameters must be made through accessing the Service Menu and adjusting things physically by manipulating the radio controls. But I am sure it is not the way Anytone do it in the factory. There would have to be a program in order to achieve this quickly and acurately. If the Noise and the S meter reading are pissing you off and you would like to do something about it, here is a work around that you may want to try which involves changing the service menu value for RF GAIN. Its just a work around. It does not fix the problem completely, but might make it easier to live with. As long as you don't change anything else, you won't screw up the radio. I have no idea if the Anytone AT-5555N2 service menu is the same as in the CRT7900V and new strykker 955 but it is RFG you are after. The N2 has 59 settings in the service menu. You could really screw up a radio if you went nuts in the service menu. Its your fault if you fuck things up. Here is how to access the Service Menu Step 1 : Press and Hold Menu and Mode while you turn on the radio. All LCD segments will show for about 2 seconds. Step 2 : Within this 2 second window release the Menu and Mode buttons and immediately press (one after the other in order) RB, NB, SCAN, MEM, EMG The radio will enter the Service Mode. The setting you are after is CH-52 RFG To check the value for any menu just key the mic. The default for RFG seems to be around 86 for all brands. Take a note of what your setting for CH-52 is before you do anything further. To alter the value press and hold the PTT while rotating the VFO up or down. I set the RFG on my N2 to 105. Up from 86. Turn the radio off and the radio will turn on with the new value. Reduce the RF gain about 10% and the noise should clear up and the volume will need to be increased to compensate but it will make listening much nicer. The RF gain is reduced and the S meter will not read as high. Turn the RF gain up and suddenly the noise will be back along with a big increase in signal. Just like turning on an rx preamp. I wouldn't call it a fix by any means but is is a work around for the time being and might be appreciated by some users.

 

[magnuman]

Received a new post from DAVID DONALDSON's (91DD018) blog today titled "ANYTONE AT-5555N2 and S5 -7 NOISE."
Evidentally there is a problem with this model and its clones where a S5 to S7 noise level is always present in receive. David has come up with a nice work-around that alleviates the problem somewhat. I have reprinted the post from David's Blog below. I'm certain it will be of interest to many of our members.

NOTE: In the past whenever I reposted one of David's posts, some nitwit from New Zealand always accused me of trying to take credit for David's work. Evidentally this clown can't read, as I always give credit where credit is due. Just putting this out there in advance.

- 399
#################################################################################################################

91DD018

AnyTone AT-5555N2 and S 5-7 Noise.​

David Donaldson Feb 14 Reports are coming in of noisy receive and S7 S meter readings with no signal on newer Anytone AT-5555N2's and several of the derivatives. It is certainly real. I have it on mine. I have no idea what causes it. Is it a design change, a component issue or a software issue. Fingers crossed it is software and an easy fix. The N2 does have software to install frequencies but I do not know if the same cable with different software can be used for updating the firmware or Service Menu settings in these radios. If it is possible, Anytone are keeping very quiet about it. So far as we are presently aware any changes to the radio's working parameters must be made through accessing the Service Menu and adjusting things physically by manipulating the radio controls. But I am sure it is not the way Anytone do it in the factory. There would have to be a program in order to achieve this quickly and acurately. If the Noise and the S meter reading are pissing you off and you would like to do something about it, here is a work around that you may want to try which involves changing the service menu value for RF GAIN. Its just a work around. It does not fix the problem completely, but might make it easier to live with. As long as you don't change anything else, you won't screw up the radio. I have no idea if the Anytone AT-5555N2 service menu is the same as in the CRT7900V and new strykker 955 but it is RFG you are after. The N2 has 59 settings in the service menu. You could really screw up a radio if you went nuts in the service menu. Its your fault if you fuck things up. Here is how to access the Service Menu Step 1 : Press and Hold Menu and Mode while you turn on the radio. All LCD segments will show for about 2 seconds. Step 2 : Within this 2 second window release the Menu and Mode buttons and immediately press (one after the other in order) RB, NB, SCAN, MEM, EMG The radio will enter the Service Mode. The setting you are after is CH-52 RFG To check the value for any menu just key the mic. The default for RFG seems to be around 86 for all brands. Take a note of what your setting for CH-52 is before you do anything further. To alter the value press and hold the PTT while rotating the VFO up or down. I set the RFG on my N2 to 105. Up from 86. Turn the radio off and the radio will turn on with the new value. Reduce the RF gain about 10% and the noise should clear up and the volume will need to be increased to compensate but it will make listening much nicer. The RF gain is reduced and the S meter will not read as high. Turn the RF gain up and suddenly the noise will be back along with a big increase in signal. Just like turning on an rx preamp. I wouldn't call it a fix by any means but is is a work around for the time being and might be appreciated by some users.

In the interest of disclosure, this walk around was developed in conjunction with Pez a member of this board also. It was all his fault for having an earlier radio that did not exihibit the noisy receive and wayward S meter reading.

 

[magnuman]

In the interest of disclosure, this walk around was developed in conjunction with Pez a member of this board also. It was all his fault for having an earlier radio that did not exihibit the noisy receive and wayward S meter reading.

A link to a video of the work around in action

 

[FredTx63]

Magnuman,

What is increasing the value of RFG actually doing? Initially I thought oh they're decreasing the receiver sensitivity, but then why would turning the RF gain knob down be necessary afterwards. I agree it seems like a decent fix, just want to understand what's happening with the radio with this workaround.

Thanks for sharing! I'm on my 2nd 5555n II and I also have a 955 v2 that exhibit these exact receiver characteristics.

 

[magnuman]

Magnuman,

What is increasing the value of RFG actually doing? Initially I thought oh they're decreasing the receiver sensitivity, but then why would turning the RF gain knob down be necessary afterwards. I agree it seems like a decent fix, just want to understand what's happening with the radio with this workaround.

Thanks for sharing! I'm on my 2nd 5555n II and I also have a 955 v2 that exhibit these exact receiver characteristics.

I don't know the answer to that Fred! My initial thought was to reduce the RFG and see what it did but it did nothing to alleviate the noise. My gut feeling is that there are probably several other service menu adjustments that would help the situation. It has also been reported that there is bleed through from nearby AM broadcast stations when using the NR so perhaps a Hi pass filter in line might help. Worth trying.
We have to bear in mind it is Anytone's first rattle out of the box with DSP so it may take a while to get it sorted, but they usually do especially when other brands are using these boards in their radios and they will push for change.

 

[FredTx63]

One more thing, Magnuman -

Have you noticed enabling the NB on your 5555n II seriously decreases adjacent channel rejection? Like significantly more so than on other radios?

This is noticable during the day when 11m is hopping and full of strong/splattering signals. I can be on a relatively quiet frequency (in terms of signals and adjacent splatter) and flip the NB on (to fight some kind of local impulse noise) and my S meter reading and received noise actually goes up.

 

[magnuman]

One more thing, Magnuman -

Have you noticed enabling the NB on your 5555n II seriously decreases adjacent channel rejection? Like significantly more so than on other radios?

This is noticable during the day when 11m is hopping and full of strong/splattering signals. I can be on a relatively quiet frequency (in terms of signals and adjacent splatter) and flip the NB on (to fight some kind of local impulse noise) and my S meter reading and received noise actually goes up.

Oddly enough I seldom use the noise blanker but your findings dont surprise me. I am sure it is all tied into the noise issue in some way. The fact the early N2's worked fine should point the way for anytone to fix the problem.

 

[Pez]

Hi all,

I am going to see if I can find out anything more from the factory about this. I have an AT-5555Nii and a CRT SS-7900V on my bench and neither have this problem - they are perfectly quiet - but Magnuman's AT-5555Nii definitely does have the problem!

And as a test, if I increase my RFG setting on a good radio to see what happens, I will see the large instant 'step' of RF gain in the RX too - it changes the linearity of the RF Gain knob on the front panel and seems to drive the internal RFG circuit very differently, to a point where it goes full ON, like a switch - but not in a good way on my radio (which again, my radio not have the problem that Magnuman is having).

73

 

[Pez]

One more thing, Magnuman -

Have you noticed enabling the NB on your 5555n II seriously decreases adjacent channel rejection? Like significantly more so than on other radios?

This is noticable during the day when 11m is hopping and full of strong/splattering signals. I can be on a relatively quiet frequency (in terms of signals and adjacent splatter) and flip the NB on (to fight some kind of local impulse noise) and my S meter reading and received noise actually goes up.

Hi Fred,

FYI - I have done a detailed explanation of this in the other AT-5555Nii thread.
TLDR: it is not a problem with adjacent rejection, its the way the NB algorithm works, at an IF / SDR level. It works GREAT - but those images/artefacts are the trade off. The key is to ONLY use NB when you need it. And don't use it, when you don't!

73

 

[FredTx63]

Hi Fred,

FYI - I have done a detailed explanation of this in the other AT-5555Nii thread.
TLDR: it is not a problem with adjacent rejection, its the way the NB algorithm works, at an IF / SDR level. It works GREAT - but those images/artefacts are the trade off. The key is to ONLY use NB when you need it. And don't use it, when you don't!

73

The noise blanker doesn't have this dramatic of a negative effect on any other DSP radio or SDR that I have. And I use a noise blanker often at my QTH and when mobile. I'm very familiar with effects of turning NB on across many radios cheap and expensive (From rci 2950dx to Apache Labs Anan 7000 DLE MK II). And I've heard you parrot the SAME thing in numerous threads. I'm also not new to radios, I don't run a NB when I don't need it or any noise filtering tool for that matter. Something is goofy with the NB on the two Q5N2s that I've had in my possession.

 

[unit_399]

I am going to see if I can find out anything more from the factory about this. I have an AT-5555Nii and a CRT SS-7900V on my bench and neither have this problem - they are perfectly quiet - but Magnuman's AT-5555Nii definitely does have the problem!

PEZ -
As a suggestion, I think you should look at all of the settings in the service menus on the 5555 and the SS-7900v that are on your bench, and compare them with the settings on a radio that exhibits the noise problem. If the settings differ between the good rigs and the bad ones, then try changing the settings on the bad guy and see it it kills the problem.

just a thought.

- 399

 

[FredTx63]

The noise blanker doesn't have this dramatic of a negative effect on any other DSP radio or SDR that I have. And I use a noise blanker often at my QTH and when mobile. I'm very familiar with effects of turning NB on across many radios cheap and expensive (From rci 2950dx to Apache Labs Anan 7000 DLE MK II). And I've heard you parrot the SAME thing in numerous threads. I'm also not new to radios, I don't run a NB when I don't need it or any noise filtering tool for that matter. Something is goofy with the NB on the two Q5N2s that I've had in my possession.

I'd imagine the Q5N2's NB is implemented in IF too. That reminds me, does anyone have a schematic for this thing?

 

[Pez]

The noise blanker doesn't have this dramatic of a negative effect on any other DSP radio or SDR that I have. And I use a noise blanker often at my QTH and when mobile. I'm very familiar with effects of turning NB on across many radios cheap and expensive (From rci 2950dx to Apache Labs Anan 7000 DLE MK II). And I've heard you parrot the SAME thing in numerous threads. I'm also not new to radios, I don't run a NB when I don't need it or any noise filtering tool for that matter. Something is goofy with the NB on the two Q5N2s that I've had in my possession.

Parroting? - people keep asking so I keep answering. Sorry if that's a problem for you.

It's just how NB is on this platform. YES, it is different because it's not hardware based like on your 2950DX, and it's not adjustable in software like on your Anan. And that is not going to change any time soon, it's the only way they can do NB on this platform, I have spoken to the factory about this (and the FW does not have provision for it to become adjustable in the future, they told me).

FWIW, on the few occasions I have needed NB on the 5555Nii, (like in heavy rain static) it has worked great. If I needed NB ON all the time because of some constant interference source then that might be a different story?. But I don't, so I'm good.

 

[magnuman]

The noise blanker doesn't have this dramatic of a negative effect on any other DSP radio or SDR that I have. And I use a noise blanker often at my QTH and when mobile. I'm very familiar with effects of turning NB on across many radios cheap and expensive (From rci 2950dx to Apache Labs Anan 7000 DLE MK II). And I've heard you parrot the SAME thing in numerous threads. I'm also not new to radios, I don't run a NB when I don't need it or any noise filtering tool for that matter. Something is goofy with the NB on the two Q5N2s that I've had in my possession.

Take it easy Fred. We are just trying to help. Dont let it get personal.

 

[Pez]

PEZ -
As a suggestion, I think you should look at all of the settings in the service menus on the 5555 and the SS-7900v that are on your bench, and compare them with the settings on a radio that exhibits the noise problem. If the settings differ between the good rigs and the bad ones, then try changing the settings on the bad guy and see it it kills the problem.

just a thought.

- 399

Thanks 399 I have actually had a quick look at this - the settings are roughly the same.

When Magnuman and I were playing around with this, we half expected to see a big difference in the service menu settings between my radio and his, but the settings were basically the same.

I'm thinking (assuming) it could be a hardware change that has happened, that the firmware hasn't quite matched up with yet. There are no schematics or anything like that available from Qixiang, so it is all a bit of a guess at this point.