Stalker 9 "slightly" off frequency on USB

[MiXiN]

I've got a Stalker 9 with mid & hi, and a Stalker 9 FDX with UK 27/81.

The Stalker 9 FDX is spot on in all aspects, however, the Stalker 9 is "slightly" off frequency on USB Tx.

I've been told that when I'm on 27.555 USB that I'm on 27.5548 - just a tad off frequency.

Rx is great, output power on all modes is spot on, but the USB TX is slightly off - so please would someone be so kind as to tell me what needs adjusting?

I have the correct alignment tools here.

[cb4ever104]

I have the correct alignment tools here.

Do have a have a decent bench frequency counter ?

[ch25]

... or a friend with HF rig to listen you? If RX stays in place just adjust VR6

(Corrected VR nr)

[MiXiN]

Yes, guys, I've got both a frequency counter & have an HF rig (Icom 7300).

[cb4ever104]

... or a friend with HF rig to listen you? If RX stays in place just adjust VR3

I think it's VR6 on the Stalker . Well it is on the JACK , and I think the pcbs are the same .

[cb4ever104]

Yes, guys, I've got both a frequency counter & have an HF rig (Icom 7300).

If you have the correct test equipment , then I'd go through and set up the carrier osc section . Leave the radio on for 30 minutes before adjusting .

Capture.JPG

Sammy

[bigpimp347]

no body in this world is on 27.555 when on USB

as for 20hz what radio are they using ?
is their radio on frequency ? i mean i've seen many a HF set off frequency and seen people set radios up to the manual and they're still off frequency.
so what's right and whats wrong ?

and anyone who's says 27.555 is on frequency on USB should stick to channel 19.

[MiXiN]

Thanks for the replies, guys.

I adjusted VR6 as suggested, but it only altered the TX freq' on LSB.

Are you sure it's this specific VR that alters the USB frequency?

[cb4ever104]

VR6 is used on the TX line to add capacitance to the main 15.4825Mhz oscillator crystal . It affects both USB and LSB .

Did you go through the whole alignment procedure ?

[MiXiN]

VR6 is used on the TX line to add capacitance to the main 15.4825Mhz oscillator crystal . It affects both USB and LSB .

Did you go through the whole alignment procedure ?

I didn't proceed with the full alignment procedure as everything else is to spec' apart from the very slight USB frequency being off.

The people on CB rigs say I'm pretty much bang on frequency, but I've had numerous people on HF rigs saying I'm off frequency without even asking.

I too am surprised that as little as 20Hz makes a difference, but it seems to be to a few people.

[cb4ever104]

From what you stated before. It's not 20hz. It's 200hz. 555000-554800. If you have the correct test equipment I see no reason not to give the oscillator section a check. The radio is 40 years old. Anyway. It's up to you.

Sammy

[MiXiN]

Got it sorted & did a full retune as suggested.

Many thanks for the input fellas.

[cb4ever104]

Glad to hear it