Batboard

VHF saber with no output power. I can hear it on a scanner but no output
at the antenna. The red led on top does not come on. The radio does
receive and then the red led works. H43QXN7139CN
I'm thinking the PA module is bad? Everything in the RSS is set to high
power output.
Is the red led on top linked to actual power output when transmitting?
I did try another good PA but no good.
Here's another thing I just tried. When setting the output bias to low in
the service section then the led works. Still no output????
Haven't gone as far as testing outside case yet.
What's going on here?
Thanks
Dennis

Are you using a PS mic with the supplied antenna?
Have you checked the internal connection to the antenna?

Those have a tendency to become weak and spread open enough to prevent
the RF from making proper contact with the internal antenna and the rear Accy. port as well.

The connection is on the upper left side of the controller board, it is "M" shaped, try pinching the center wires together just enough to make contact.

The LED is tied to the controller to indicate PTT switch closure, but does not represent actual RF output, that is set up in the service section of the RSS.

Gopod luck!

73!

Checked the battery or power supply?

Fowler

saberjerk wrote:VHF saber with no output power. I can hear it on a scanner but no output
at the antenna. The red led on top does not come on. The radio does
receive and then the red led works. H43QXN7139CN
I'm thinking the PA module is bad? Everything in the RSS is set to high
power output.
Is the red led on top linked to actual power output when transmitting?
I did try another good PA but no good.
Here's another thing I just tried. When setting the output bias to low in
the service section then the led works. Still no output????
Haven't gone as far as testing outside case yet.
What's going on here?
Thanks
Dennis

That's an RSS option. Don't count on it for anything. LED on RX, or LED on low battery are the only options, IIRC.

Hi
I am just using the radio, no accessories attached.
The battery is new and fully charged and works on other sabers.
The red led comes on when receiving a signal and the sensitivity
is excellent. I don't think there is an antenna connection problem
but need to check it.
Like I said the red led comes on for transmit only when I set the
bias to low in the RSS service section???????????
If the led is just a PTT indicator then why doesn't it come on every
time the PTT is pushed?
No one ever seen that before????????

Guess no one can help.
I sure miss Monty.

i had that problem with a uhf saber .. its not the pa ... im trying to rember what module was bad ... i think it was the one just above the pa.... i dont have my book handy to rember what it is called..

and yes , the light will not come on if there is no transmit power .

FDS? Filter Detecter Switch.

Looking at the schematic the led is driven directly from the main microcomputer and is not connected to any other components.

The FDS module (above the PA) appears to control all the RF switching and has several lines that receive information for control and others that report back.

I would replace that and see what happens.


mancow

Actually when I tried another PA I replaced all the modules with the
higher bandsplit. No go.
I could hear the radio on the scanner but no output.
What's with setting the PA bias? When I set it to low in the rss
the red led does come on. Still no output.

Greetings:
Tonight, I after I drove home, I removed my Saber from the SVA and turned it off and went inside.
A few minutes later, I turned it back on only to find that the PTT switch didn't work, but when I adjusted the vol. pot, the radio went into transmit, then a clockwise turn of that same control shut off the transmitter.

I did some detective work and found that the rear cover had a slight bend in it and caused the short to occur, which by trial and error, also cut off the PTT, and monitor button all at the same time....RX but no TX, and no LED either.

I added a touch of superman to the rear case, re-read the radio, went through the service menus and reprogrammed, but the case re-flexing did the trick.

The frame can be easily bent, and this was part of my problem as well as it causes the frame to somehow "lose" ground conductivity which causes the side buttons to also stop functioning.

After a caseless trial adjustment, all is now well again and the radio is back to "normal" operation.

Just strange that this happened in a 50 foot walk to the house, and never having dropped the radio to cause this problem, but I felt I should share it in case this is another clue to this poster's difficulty.

Hope this helps................

73!

Hi
I don't think this is my problem.
If you read my previous posts you will see that if I
change the bias to the pa to low that the PTT button functions
normaly and the red led does light. Still no output though.
So I don't think there is a short.

Well we have a couple conflicting answers here.
Someone thinks the red led is just a PTT indicator and
someone else thinks it's an indication of power output.
Which is it??

The LED is an indicator for PTT, driven by the microcontroller. It can also be programmed to work as an Low-Battery-Indicator. That means the LED will blink in TX-mode, if the battery-voltage will drop below an certain value (can be adjusted via the service menu). The LED is not able to work as an RF-indicator. Remove the PA module from a working radio and you will see the LED will still lit on TX.

Use an MX1000 testcable and check, if there is power on the ACC-connector. If not, check the current during TX-ing. High-current (exact value depends on the power of the radio) means that the PA is working, but maybe the switch-module is faulty and dont passes the power to the right ports (OK, on some strange defects the PA is not working, but it still draws some amps). Small current: check, if the PA-module gets the proper voltages (Manual needed!). When you can hear the Saber on a nearby scanner, at least the PLL-module is working. So it is also a good idea to check, if there is the same amount of RF on the input-pin of the PA-module, like it is on the output-pin of the PLL. Normally the ouput of the PLL is directly linked to the PA-module. But maybe it dont reaches the input of the PA-module to drive it. I have an MX300-R in front of me, with the same problem = broken mainboard. Damn multilayer stuff.....

Keygun

The red led also lights when a received signal is present.
Like I said in above posts. The red led will light when the ptt is pressed
only after I set the PA bias to low in the rss.
I do get a good signal on the scanner but no power output on
a power meter.
I need to find another radio to do the module swapping thing. Then
when I verify the modules are good I can attack the board.
Thanks
Dennis

Update.
The filter/detector/switch module was bad. Cracked hybrid substrate.
Now I have power output.
Red led still does not light with PTT.
It does light with received signal though

is it a regular saber or a syssaber ???

It's a regular saber as you can see from my first posting of the model number. H43QXN7139CN