Low band Syntor X9000 squelch question

[Jim202]

Have a low band Syntor X9000 that seems to have the squelch right on the point of breaking squelch. The radio
default setting is at 4. That is the top setting in the software. I can change this with the HCN1073A control head.
When I do this, it will open the squelch, so I know that part is working.

Not having a low band manual, I am sort of at the point of asking for some pointers. Is there an internal adjustment
that I am not aware of on one of the circuit boards? I have located the RF output adjustment, the TX current limit
adjustment and the deviation control. Beyond that, don't have a clue.

Have 2 other units that work just fine. Have moved the heads around and it doesn't seem to change anything.
The issue stays with the radio. Have even tried different control cables. Problem stays with the radio.

Jim

[Bill_G]

I'll check tomorrow. Used to do a lot of low band work on logging trucks, and some were synx9k.

[Bill_G]

Got your info - According to the manual (yea! my memory was right) there is a threashold adj pot on the microcomputer board. It's tucked in behind the micro-p housing between two hybrids and the audio output transformer.

[Jim202]

Thanks for the info. I will pop the case in the morning and see if I can locate it. At least I have it on
he bench with another control cable. Makes it much easier to play with it. Just short a head, so that
has to get moved around with the radio.

Jim

Got your info - According to the manual (yea! my memory was right) there is a threashold adj pot on the microcomputer board. It's tucked in behind the micro-p housing between two hybrids and the audio output transformer.

[Jim202]

Update for those that play with or own the Syntor X9000 radio. The squelch pot only functions in the 1 and 2 squelch setting. In the 3 and 4
position, it has no effect. Found this out from some other sources.

As the radio I have on the bench wants to continue to pop open the squelch with some very weak signals, I am still trying to locate the actual
manual documentation on the circuit board diagram and board layout. I suspect I need to move up the squelch threshold setting point and
need the circuit diagram in order to be able to make a circuit mod.

Jim

[com501]

Since this radio is older than a Spectra you might want to look at capacitive components in the receiver IF for value changes, also the audio squelch circuits before hacking anything. Chances are, a group of components have deteriorated enough to cause your problem.

[Jim202]

I would spend considerable time on the bench with this radio once a service manual becomes available. There are a couple of people that are working to make the service
manual available for a low band model of this radio. Not really sure the issue is in the IF though. The sensitivity is good and the signal is real. If I remove the
antenna to the radio, the squelch popping open goes away. It is not constant and is frequency dependent.

I have just been looking for a way to slide the squelch threshold setting to a tighter squelch. In normal radios they open with a 1 or zero setting, depending on
where the variable pot is set. This radio is real loose with the pot up tight on the #2 setting. As the variable pot only works in the #1 and #2 position, I don't
have to worry about it in the #4 position. Something else in the chain is causing the low threshold.

Jim

Since this radio is older than a Spectra you might want to look at capacitive components in the receiver IF for value changes, also the audio squelch circuits before hacking anything. Chances are, a group of components have deteriorated enough to cause your problem.

[Pj]

Simple thing to try... is the extender on, off or user selectable? It tends to lower the squelch threshold quite a bit (in the 3 that I had) at least

[akardam]

... is the extender ... user selectable?

That's news to me. Is the extender even capable of being user selectable?

[Pj]

Yup. Its a selectable option under the mode? screen in the radio RSS and then you program EXT indicator button in the control head program.

[akardam]

Well I'll be a son of a gun. Learn something new every day.