CRT SS9900 (Anytone 6666) High SWR warning issue

[Dereka5]

I just purchased a CRT 9900, and although all functions work, the SWR warning issue (Tsr) is problematic.

On low power (FM/AM) even with Antenna completely disconnected, there is no warning and no auto' rig cutoff at anything between 1.5W to 20W.

When RF power is 20W or more, though, the high SWR warning & radio cutoff functions fine.

One other issue with this is that the rig SWR readings are very inaccurate throughout the band; 2.5:1 on an external SWR meter reads something like 1.5:1 on the rig, and well into the red externally reads around 2.1:1.

Anyone know what the problem may be with the SWR warning/cutoff issue, and is anybody elses rig SWR readings well out compared to the correct readings?

 

[AudioShockwav]

I am running a SS9900 in my pickup.
Checking with a external SWR meter it was within .1 of the internal meter.
I have had no issues with built in SWR function so far regardless of power settings.
We're did you purchase the radio?
I imported mine from the UK directly.

73
Jeff

 

[Handy Andy]

The AT - 6666 SWR sensor - at least they call it that...

​

Is nothing more than a Ferrite Core wound with wire and coax strung thru it - this is their sensor.
IF the wires in the sensor are not soldered, RF can't pass thru to the center lead of the antenna connecter right behind it - you'll need to reflow some solder and do continuity checks to make sure the connecter center pin routes thru past the SWR sensor - have to do this to make sure the SWR condition is not internal like a broken solder joint. - check for shorts as well.

Tighten all case screws and if needed, reflow solder from the side panel lugs to the main PCB ground foil.

This sounds like a dropped radio problem - but cracked boards require a replacement - you can try to reflow solder but it's only a low-power quick fix sort of thing - the torn foil has lost the ability to conduct so trying to jumper over it with solder - remember this is RF so be careful and use a magnifying glass too - no errors here or the radio gets it. (poof)

​

 

[Dereka5]

I purchased mine also in the UK from the well known auction site.

I'm led to believe it's the latest V4.

 

[Dereka5]

The AT - 6666 SWR sensor - at least they call it that...

View attachment 46225
​

Is nothing more than a Ferrite Core wound with wire and coax strung thru it - this is their sensor.
IF the wires in the sensor are not soldered, RF can't pass thru to the center lead of the antenna connecter right behind it - you'll need to reflow some solder and do continuity checks to make sure the connecter center pin routes thru past the SWR sensor - have to do this to make sure the SWR condition is not internal like a broken solder joint. - check for shorts as well.

Tighten all case screws and if needed, reflow solder from the side panel lugs to the main PCB ground foil.

This sounds like a dropped radio problem - but cracked boards require a replacement - you can try to reflow solder but it's only a low-power quick fix sort of thing - the torn foil has lost the ability to conduct so trying to jumper over it with solder - remember this is RF so be careful and use a magnifying glass too - no errors here or the radio gets it. (poof)

​

Cheers as always for your good input, Andy.

I'll have a peep inside my rig tomorrow around the Toroid area.

If all seems in good shape, is there any modification I can do to this "SWR sensing" area to bring the readings more inline with the correct SWR readings as seen by a good external SWR meter?

 

[AudioShockwav]

I purchased mine also in the UK from the well known auction site.

I'm led to believe it's the latest V4.

If it goes down to 12 meters (24 mhz) it is a v4.
I dont know for certain, but there should be a way to calibrate it in the service menu.
The problem with that is finding the info.
I suggest you try e mailing the retailer you purchased from, or even CRT , tell them what the issue is and see what you get.
CRT France claims a 2 year warranty.
Did you get it from Jabber products?

73
Jeff

 

[Handy Andy]

Here's the problem...

And its not good...​

The schematic above, I wanted to pass along that the CAL-ibrate (CALL) and SWR are preset values the radios CPU board has their outputs as SWR DET and CALL DET - these are the end result filtered down ones from the detector toroid coil (that bottom snapshot) that heads off to the CPU.

So you know, the CPU is not infallible.

The CALL line is supposed to be a small current used to reference the larger current (FWD) out the antenna - the difference between the SWR (Reflected) and CALL (Forward) is done back at the CPU thru an INTERNAL comparator and a single result is then looked at and the CPU acts accordingly if the readings are good, you move forward and talk, if they are not - it folds back shutting down the VCO if needed to keep the system from failing.

There are several reasons that can occur to make this condition - one was the dropped radio - damaging the case and for foil traces making this a hard one to track down and repair.

The other ones are Finals going bad, or the input section the Antenna connector itself - received a STATIC poke from an external source (Lightning or even general static) and it may mean that someone returned it - they threw it on an SWR meter -found it worked and resold it.

Although I didn't accuse anyone, sh*T does happen and you get a radio that may have been dropped or spiked by someone and returned they reshipped to you - best to get rid of that darn thing and ask for another.

Why? Look above, you do not have any method of adjustment and a VERY long trace back to the CPU for SWR and CALL lines - they don't give you a trimmer cap - they put in a preset value and you run the radio with it - period.

The Low setting to High setting tells me the radio got "spiked" or dropped - something is broken in it - return it while you still can - you don't want to mess with this unknown condition - it could mean serious consequences later.

The Menu won't clear a condition caused by errant spikes in the lines it uses to sense - for once the level is "Set" any simple spike from poorly soldered, loose parts - will generate a larger offset condition.

The radio will still shut down, the MENU setting is not set up for variables - hence your issue. You can try to figure out the SWR "limit" function manually or even use the programming cable - but something is not right - you should return it for service or refund, or exchange for another.

 

[Dereka5]

Many thanks for the great response as always, @Handy Andy.

I was going to have a look inside this if it was a possible easy fix, but with what's been mentioned it sounds like a faff so I refrained.

The "dropped radio" is a distinct possibility, because this Radio was sent in its original box - only sent in a thin jiffy bag - so not protected from usual mail abuse, bumps, or bangs, in the slightest.

At first I eMailed the seller a couple of times to ask for a prepaid label to return this for an exchange, but the seller is completely ignoring me, no response whatsoever, presumably hoping I'll go away, so I've been forced to open a PayPal dispute.

His business number isn't in service, too, so there's no means to have a Telephone conversation with him.

@AudioShockwav - yes, the seller is Jabber Products & based on my experience, he's best avoided.