Anytone at5555n II high swr on ssb , low swr on am and fm

[Geoexplorer69]

Hello everyone,
I am a new user on this forum and have been looking over the threads on the Anytone at 5555n II to see if I could find a solution, as of yet I cannot find any. I’ve also googled my issue and beyond a couple articles sort of dealing with this I cannot seem to locate any solutions.

Let me give a little background information on the radio, I purchased it on eBay as a brand new “open box” radio with all accessories included, upon receiving the radio I took it out of the box and immediately noticed that the security labels on the sides of the radio were missing so that led me to believe that somebody had been inside the radio clipping the wires and doing the mod mod .
With screwdriver in hand I opened the radio and confirmed my suspicion. It had indeed been clipped and modded.

I hooked it up to a good coax and power supply and a good antenna , using an external SWR meter I checked the SWR on channel 1 and channel 40. I had to do some minor tweaking to the antenna to get a 1.1 to 1.3 SWR across all channels one through 40 on a.m. and FM when I went to check the SWR inside band, my SWR immediately jumped to 2.9 to 3.2 which is unacceptable ,

So I’m reaching out to anyone who might be of help ,
Cheers

 

[Eldorado828]

Welcome to the forum!

What kind of shape is your jumper cable in from the radio to the swr meter.

Also what swr meter and antenna? The more info, the more people can paint a mental picture for investigation.

 

[Pez]

It could have had the service menu messed with - potentially causing a PA / oscillation problem to occur due to incorrect bias settings, or by the incorrect adjustment of other settings relating to the TX stage.
Returned radio's that have have the service menu messed with are a big problem. There are not too many people who have all the information and all the equipment needed to align these radios the right way.

 

[TM86]

If have or can borrow a known good dummy load see how the radio reacts to that.

 

[Geoexplorer69]

First off thank you all for the response,.I’m an old ham that’s been out of the game for 30 years and I did serve 3 years a a signal man in the 82nd Airborne Division 19801983 . So I have some background in communications.My mos was 31M but was cross trained on all radios vhf/ uhf ect including satellite comms as well.
To answer your questions
1) my swr meter is a brand new surecom vswr & power meter. HF 1.5-70 mhz and it jives with the on board swr meter on the radio within a 10th .

The patch cord is a brand new one 1’ long with pl259 connectors .

I don’t have a good dummy load like a “bird “ or access to one but I have been thinking of purchasing one .

Before anyone asks The antenna is a fire stick 4’ on a tram triple magnet mount with good rg8x coax (no bends or kinks w/ good connections) well grounded tested with a multi meter.

I am leaning towards the response regarding the “service menu “ being tampered with because as I said in my first post I discovered the “so-called new open box actually included opening up the covers an doing the mars mod “.lol.

I just ordered a brand new Anytone at5555n II factory sealed and rather than ditch the old one and chalk it up to eBay scam I want to see if it’s repairable so I can use it on a vehicle.

Thanks to everyone
Roger

 

[Pez]

First off thank you all for the response,.I’m an old ham that’s been out of the game for 30 years and I did serve 3 years a a signal man in the 82nd Airborne Division 19801983 . So I have some background in communications.My mos was 31M but was cross trained on all radios vhf/ uhf ect including satellite comms as well.
To answer your questions
1) my swr meter is a brand new surecom vswr & power meter. HF 1.5-70 mhz and it jives with the on board swr meter on the radio within a 10th .

The patch cord is a brand new one 1’ long with pl259 connectors .

I don’t have a good dummy load like a “bird “ or access to one but I have been thinking of purchasing one .

Before anyone asks The antenna is a fire stick 4’ on a tram triple magnet mount with good rg8x coax (no bends or kinks w/ good connections) well grounded tested with a multi meter.

I am leaning towards the response regarding the “service menu “ being tampered with because as I said in my first post I discovered the “so-called new open box actually included opening up the covers an doing the mars mod “.lol.

I just ordered a brand new Anytone at5555n II factory sealed and rather than ditch the old one and chalk it up to eBay scam I want to see if it’s repairable so I can use it on a vehicle.

Thanks to everyone
Roger

Welcome!

I would try a different antenna if you can also. Mag mounts are often bad news, they can cause all sorts of issues with common mode current, poor grounding (even when it tests ok with a multimeter), etc.
Hopefully you will end up with 2 good radios. You can't ever have too many! haha
73

 

[Geoexplorer69]

Welcome to the forum!

What kind of shape is your jumper cable in from the radio to the swr meter.

Also what swr meter and antenna? The more info, the more people can paint a mental picture for investigation.

I wanted to thank you for your reply and say that here is SW Arizona I have heard you loud n clear a few times when I I had my ft891 tuned to frequency.

 

[Geoexplorer69]

Welcome!

I would try a different antenna if you can also. Mag mounts are often bad news, they can cause all sorts of issues with common mode current, poor grounding (even when it tests ok with a multimeter), etc.
Hopefully you will end up with 2 good radios. You can't ever have too many! haha
73

Well thank you for the response, yea I can hope or at least have a few spare parts, lol. I am pretty confident in the mag mount considering it gives such a low swr on am and fm and only acts up on SSB with a 2.9 or 3.2
Am and fm gives me 1.2-1.3 across all channels 1-40.

I am looking at a new base station antenna leaning towards an A99 or just bite the bullet and get a Serio 5/8 wave .

 

[9C1Driver]

Is your watt meter designed to read SWR in all modes? You normally only check SWR in AM or FM modes with just a carrier.

 

[Geoexplorer69]

Is your watt meter designed to read SWR in all modes? You normally only check SWR in AM or FM modes with just a carrier.

You know that’s a good question,
I will look at that. I still can’t believe that the onboard swr meter and the Surcom swr meter can both be so close in their measurements and have the Surecom not work on SSb considering the Surecom is labeled HF 1.6-70Mhz 120w Given my understanding that HF bands are most but not always SSB. I will explore that more thoroughly.
If you have any other suggestions please share them with me. I appreciate your help
Thank you

 

[Geoexplorer69]

Oh and btw everyone I have been studying up to get my ham tickets once again. After 30 plus years so one day You will hear me on whatever band is open . Guess I’d better hurry so I can catch some good solar cycles.
73s

 

[Geoexplorer69]

Update on the Anytone at5555n II
Well I have changed out the antenna today, still same swr problems on SSb . Now new issues have come to light. Not going into all of them , just suffice it to say my diagnosis is the radio will now become a doorstop/parts machine. I have a brand new replacement radio on the way should be here Saturday or Monday. The radio is factory fresh no mods and I do not intend to do any mod beyond the 11m mod .

Thanks to everyone who came up with possible solutions I will report on the new radio soon.
Cheers