IC746 strong birdies on HF/6m

[VK2KRR]

Since Ive moved shacks, ive noticed I am getting very strong birdies every 100 KHz on my IC746PRO.
This happens even with NO coax plugged into the antenna ports. Plugging an antenna in makes no difference to the strength.
The birdie is S9 with no pre-amp switched in from 1 MHz to 30 MHz. Switching in the pre-amp makes no difference to strength.
I have switched off all power and electrical devices around the house and its still there.
Does this radio have major problems ??
Its still present at 50 MHz but only to S5 level. Its still there at 144 MHz but no strength.
I noticed that my no TX issue seems to have dissapeared also ? and it works again. All very strange.
But does this sound like a radio related issue rather than a birdie?

[VK3HZ]

Are you running it from a switchmode power supply?
If so, try running the rig on a battery to see whether it's the PSU gone crazy

[VK2KRR]

No, its the usual noisy transformer Electrophone 35A supply. Runs the IC910 also

[VK4ADC]

Leigh

There is an internal CAL.MARKER feature used when calibrating against WWV or other frequency standard. Is it possible that you went into this setup mode and forgot to turn it off ??? Maybe if you went back into it, turned it on then turn it off again before exiting might do the trick. Alternatively, try a CPU reset.

Section 13 of the user manual, just after CPU resetting, deals with freq cal procedure.

73 Doug VK4ADC

[VK2KRR]

Doug
Possibly, I'll check that out.

[VK2KRR]

Oh my god Doug! Your a legend...
I went in a tried turning things on and off because I had this TX issue.
Thanks a lot for that, it was exactly what you said the cal.marker. No more birdies.

[VK4ADC]

Leigh

I have the IC-7400 (the same as the 746PRO - except the correct model for outside the Americas) and I went through the CAL setup a while ago to check how close it was. Fortunately, I turned mine back off.

73 Doug

[VK2OMD]

I am always amused by Icom's manuals.

I owned a 7400 for some time and had not trouble calibrating frequency to a very high order... much more than its short term or long term stability.

Here is what Icom has to say to its users:

"A very accurate frequency counter is required to calibrate the frequency of the transceiver. However, a rough check may be performed by receiving radio station
WWV, or other standard frequency signals. CAUTION: Your transceiver has been thoroughly adjusted and checked at the factory before being shipped. You should not calibrate frequencies, except for special reasons."

Haven't we been dumbed down!!!

The 7400 is one of the modern types of transceivers that derive ALL oscillators from a single master oscillator.

Here is how to calibrate it to better than 1 part in 10^7 using WWV.

• Allow the radio to stabilise thermally.
  Set it to CW mode and tune in WWV carrier for a normal CW beat note.
  Set the VOX off so you do not key the transmitter up.
  Plug a morse key into the radio and key down, or insert a shorting plug so you can hear sidetone at the same time as the beat note from the WWV carrier.
  Now adjust the rear panel freq cal pot until you get less than 1Hz beat note with the display reading 10.000000 or as appropriate.

To be clear, what you are doing here is beating the carrier beat note against the sidetone oscillator. It is a standard technique for netting to a CW station, and when the frequency of the received signal is very accurate and known, the freq calibration error can be observed.

Too easy?

This is one of the few Icoms in my experience that you don't have to pull apart and let cool down to get access to the freq trimmer. How many of you are familiar with removing the 1296 module from a '910 to calibrate 1! But they learn, with the IC-7000, you can perform this procedure from the front panel with no instruments, no tools.

Owen