Pages: [1]   Go Down

Author Topic: IC-7300 Tuning Memory  (Read 356 times)

K1KIM

  • Member
  • Posts: 1556
    • HomeURL
IC-7300 Tuning Memory
« on: August 07, 2021, 03:23:48 PM »

My IC-7300 doesn't seem to be memorizing the frequencies that were tuned prior on the internal tuner.

I believe I should be hearing the relays click softly as I move the dial across the band and pass the frequencies I tuned prior.

I just noticed this after disconnecting my external tuner temporarily.

I cleared the memory and tuned one frequency, but no relay click when passing it on the waterfall.

When I also tune that same frequency again it chatters to long for it to be "pre-tuned" and in memory. According to all the videos I should hear a click at least.

Any suggestions?
Logged
So Many Toys.......So Little Time!

K1KIM

  • Member
  • Posts: 1556
    • HomeURL
Re: IC-7300 Tuning Memory
« Reply #1 on: August 07, 2021, 04:13:47 PM »

Quote
My IC-7300 doesn't seem to be memorizing the frequencies that were tuned prior on the internal tuner.

When I also tune that same frequency again it chatters to long for it to be "pre-tuned" and in memory. According to all the videos I should hear a click at least.

I see this happen from time to time as well. In MY case, it seems to be caused by RFI. The occurrences have diminished substantially after adding CMCs.

I am confused as to what RFI has to do with the radio remembering the frequencies I have already tuned on.

I have little or no RFI. The antennas all have common mode chokes and baluns.
Logged
So Many Toys.......So Little Time!

K0UA

  • Member
  • Posts: 9589
Re: IC-7300 Tuning Memory
« Reply #2 on: August 07, 2021, 04:23:21 PM »

I don't believe it works that way at all. I don't think it "Remembers" until the PTT is pressed and then it returns back to a pre remembered frequency tune. I do NOT believe it is supposed to retune the antenna tuner as the the frequency is changed by the encoder knob while the rig in receive mode. .  At least that is the way my two 7300's work, and always have.  If you press and hold the tune button, it goes thru a complete tune cycle looking for best match, and that can be 2 or 3 seconds depending on what it finds. I think you are trying to make the rig do something it was never designed to do. Your mileage may vary, but that is what I think.
Logged
73  James K0UA

K1KIM

  • Member
  • Posts: 1556
    • HomeURL
Re: IC-7300 Tuning Memory
« Reply #3 on: August 07, 2021, 04:30:06 PM »

I don't believe it works that way at all. I don't think it "Remembers" until the PTT is pressed and then it returns back to a pre remembered frequency tune. I do NOT believe it is supposed to retune the antenna tuner as the the frequency is changed by the encoder knob while the rig in receive mode. .  At least that is the way my two 7300's work, and always have.  If you press and hold the tune button, it goes thru a complete tune cycle looking for best match, and that can be 2 or 3 seconds depending on what it finds. I think you are trying to make the rig do something it was never designed to do. Your mileage may vary, but that is what I think.

If you have a few minutes watch You Tube Ham Cured Smoke Icom 7300 A-Z  #40 and let me know what you think. It will explain that the radio is not trying to tune without the PTT or Tune button, but just clicks when it passes the frequency.

I would like you hear your thoughts James.
Logged
So Many Toys.......So Little Time!

K0UA

  • Member
  • Posts: 9589
Re: IC-7300 Tuning Memory
« Reply #4 on: August 07, 2021, 04:36:00 PM »

I don't believe it works that way at all. I don't think it "Remembers" until the PTT is pressed and then it returns back to a pre remembered frequency tune. I do NOT believe it is supposed to retune the antenna tuner as the the frequency is changed by the encoder knob while the rig in receive mode. .  At least that is the way my two 7300's work, and always have.  If you press and hold the tune button, it goes thru a complete tune cycle looking for best match, and that can be 2 or 3 seconds depending on what it finds. I think you are trying to make the rig do something it was never designed to do. Your mileage may vary, but that is what I think.

If you have a few minutes watch You Tube Ham Cured Smoke Icom 7300 A-Z  #40 and let me know what you think. It will explain that the radio is not trying to tune without the PTT or Tune button, but just clicks when it passes the frequency.

I would like you hear your thoughts James.

I will watch the video when I et some time.  And yes the radio will make some clicks, but these clicks are the bandpass filters being changed when you make large excursions in frequency. I don't believe the tuner moves at all PTT is engaged.
Logged
73  James K0UA

K0UA

  • Member
  • Posts: 9589
Re: IC-7300 Tuning Memory
« Reply #5 on: August 07, 2021, 11:21:36 PM »

I watched the video and my settings are Tuner "auto" and PTT Start "on"

I tuned an antenna with not a particular good SWR (varies from 1.5 to over 2.0 to 1) on 40 meters at 7.000 7050 7100 7150 7200 7250 and 7299.99

I rolled the VFO up and down the band and every time I got clicks at 7045,7102,and 7143.. That was all.  I got NO clicks until I got to 7300.1 and got a click and the TX icon went to the dotted outline indicating out of band. In rolling up and down the band the auto-tuner still went thru a short auto-tune cycle each time the SWR rose enough to trip it into an auto-tune cycle when the PTT was pressed.

 It just depends on where you last tuned and whether the SWR is still good enough to NOT go into an auto tune cycle. In other words if it went into an auto tune cycle at say 7030 and then you spin the VFO up to say 7260 for example where the tuned SWR would rise too high the rig kicked automatically into a short tuning cycle. 

These auto tune cycles are very short usually not much over a second, and I believe it does consult its memory as a starting place. BUT I do not see a correlation to the places that I set and did a tune as in the every 50 Khz as I outlined above. As for the three clicks at 7045 and 7102 and 7143, I cannot fully explain the why of those. You might try on your rig and see what you get after manually forcing a tune every 50 Khz like I did.

Now a couple of things I have learned from operating for a long time with these rigs. You can make the auto-tuner "try again" for a better tuning solution by holding in the Tune button for about 3 seconds and force it to do an auto-tune from scratch.  You can also force the auto-tune to tune slightly better than a 3:1 SWR by going back to a frequency that is 3:1 or better and forcing a tune there, and then moving the VFO down or up to the frequency of interest where the SWR is greater than 3:1 where if you push the tune button it will fail, AND as long as the SWR with tuner engaged is not above about 1.5 with the tuner still engaged the PTT start wont force it into a tune that would fail. So you can "get by" with this technique.

Of course you could always go to emergency mode and tune there, but then suffer the programmed in 3 dB loss of power from the get go. Of course any additional losses in the coax from the higher SWR are still there, and depending on frequency may or may not be consequential. But it is all better than the rig set to 100 watts "normal" but the foldback circuitry greatly limits the power well below 50 watts.

I have seen a modification to make the tuner tune the same range in normal power as it does in the "emergency" 50 watt power level, BUT I do not recommend doing the modification. Yes many have done the mod and claimed no harm, but my take on it is if Icom could have made the tuner tune beyond the 3:1 normal range SAFELY in all cases at the full 100 watt level they would have done so from a marketing perspective.

I hope this helped. If you would like to discuss it further with me and do real time testing, call me on the phone and we can go from there.   73  James K0UA
Logged
73  James K0UA

K1KIM

  • Member
  • Posts: 1556
    • HomeURL
Re: IC-7300 Tuning Memory
« Reply #6 on: August 08, 2021, 06:39:34 AM »

Thanks James.

I'll play with it some more and incorporate some of your thoughts.
Logged
So Many Toys.......So Little Time!

K0UA

  • Member
  • Posts: 9589
Re: IC-7300 Tuning Memory
« Reply #7 on: August 08, 2021, 06:15:30 PM »

Thanks James.

I'll play with it some more and incorporate some of your thoughts.

Cool, let me know what you come up with.  But my first impression is that your rig is not broken.
Logged
73  James K0UA
Pages: [1]   Go Up