Yaesu FTDX 1200 receiver issues?

Discussion in 'General Technical Questions and Answers' started by KJ7DX, Apr 10, 2018.

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  1. KJ7DX

    KJ7DX Ham Member QRZ Page

    Looking for thoughts on some peculiar behavior from a fairly brand new radio. I tend to be verbose so I'll just put a few of the "highlights" up top here, and then tell the whole story below. Some of the issues:

    *Distorted receive audio that seems to be isolated to 80M
    *Strange behavior of receiver after using Scope function and switching from 20M to 40M
    *Factory reset performed; no difference observed afterward
    *Window of extreme noise (S9+20) on 40M (seems isolated to 40M) that "shifts" up or down over time
    *Radio is about one week old; bought brand new; no changes in equipment/configuration/etc. at QTH

    The long version:

    Bought an FT DX 1200 new about a week ago. The radio has been working as expected. Last night, I tried out the Scope feature for the first time. Seemed to work as expected. This was on 20M. Closed out of it, switched to 40M and RX was very quiet (as if no antenna was connected; S-meter showed S0). There was a strange sound...a very faint/subdued sound, but almost like what it would sound like if someone was tuning up while spinning their VFO dial. A tonal sound that went from high to low in frequency, and repeated in a sort of regular "cycle". Switched back to 20M, all looked ok. Went back to 40M and then experienced a noise level that varied from S9+10 to S9+20 and covered from about 7.160 - 7.450 or thereabouts. Depending on the location within this window/spectrum, the noise varied from just hash, to frying bacon, to a low hum. Going down below 7.160 things seemed more normal. However, when I came back to the radio about two hours later, the noise window had "shifted down" and was experienced starting at around 7.040 and going up from there. I switched to 80M and while there was no issue like the above, all received signals sounded distorted (as if everyone had their mic in their mouths and was yelling into it). The distortion issue seemed to be limited to 80M. As of this morning, the noise I referred to on 40M has shifted again and starts around 7.200 and goes up from there. Also, I tried the full factory reset procedure last night thinking that (maybe?) the issue was related to the Scope feature and something was wrong there (like something went haywire with it and it was affecting the receiver) but that did not help/made no difference at all. No new electronic devices, appliances, etc. have been added at my QTH and no changes to antennas, setup, configuration, etc.

    Thanks for any ideas that you might have. If we come to the conclusion here that the radio does have problem(s), I'll probably havet os end it to Yaesu for repairs, instead of returning to Gigaparts, as I already mailed in the Mail In Rebate a couple days ago.

    Thanks,
    Matt
     
  2. AI6AK

    AI6AK Premium Subscriber QRZ Page

    Matthew,
    Probably not related but won't hurt to check but does the radio have the latest firmware installed? BTW, I used to live in Temecula (16 years). Moved out to Havasu full time 2 years ago.
     
  3. W1VT

    W1VT Ham Member QRZ Page

    The distortion and noise could be caused by a strong interference source external to the radio. It should go away if you switch to a dummy load.
     
    K2XT likes this.
  4. KJ7DX

    KJ7DX Ham Member QRZ Page

    Thanks for the reply. I haven't checked the firmware version. I'm at work but will check when I get home tonight. I figured it would be at least (reasonably) up to date, but I guess it depends on the manufacture date, how often Yaesu releases firmware updates, and how long it was sitting on Gigaparts' shelves.

    Even if I find the firmware outdated, I think you have to have the optional SCU-17 to update firmware on this radio, which I don't have, but I'll see if there is a potential workaround. Will let you know what I find out...
     
  5. KJ7DX

    KJ7DX Ham Member QRZ Page

    Yeah, if it had just been the atrocious noise level that came out of nowhere (not there before, then last night it's suddenly there) I'd have been less worried...would suspect a source of interference from the neighborhood (I live in a pretty densely populated suburban neighborhood). Someone getting a new plasma TV or that sort of thing. I also took a walk around the neighborhood looking at the street lights, as I've heard about them creating issues for people on 40M when they go bad, but they all looked ok (to me, anyway...no flickering, etc.)

    Did not think about the distortion also possibly being caused by external interference. If this does end up being the case, whatever the offending source is, it is something nasty. For anyone that has dealt with that type of issue, is it normal for the affected frequencies/section of spectrum to "shift" or move around like this? To resolve in some ranges, and appear in other ranges, of the same band as hours go by?

    If it is interference, I doubt it's someone's new plasma TV though...since it was still happening early this morning...unless they have insomnia and are watching that TV all night and into the morning...
     
  6. K4PDM

    K4PDM Ham Member QRZ Page

    There are no new plasma TVs. They stopped exporting them to the US in 2014.
    Was your AGC accidentally turned off? That could cause the overload-type distortion on 80 meters.
     
    KK4CUL likes this.
  7. G4COE

    G4COE Ham Member QRZ Page

    The power supply is.....? Not a switch mode is it?

    Dave
     
  8. K2CD

    K2CD Premium Subscriber QRZ Page

    Based on what you've told us so far I assume you don't have another transceiver/receiver to listen on? What are you hearing on 40M in the daylight hours? If it's related to street lights, that could possibly give you a clue. I know you said you haven't added anything new at your house, but have you tried shutting off the breakers one at a time and seeing if the noise is abated. I had a cordless telephone with a switching power supply on the base that went rogue on me, once. Coincidentally it wiped out 40M. I threw it away. As for signals sounding distorted, make sure the noise blanker if off, as that can cause distortion, especially on strong signals. When you switch to AM mode and tune around 40 what are you hearing? Please update us.
     
  9. KJ7DX

    KJ7DX Ham Member QRZ Page

    A few updates since yesterday to address questions, suggestions, thoughts so far:

    -Firmware versions checked. Confirmed that firmware in radio is current/up to date.
    -AGC is confirmed on
    -Power supply is a linear, not switching (Astron RS-35M)
    -No other radio that I can listed on (I sold my previous/older radio a couple days after purchasing this one and it's already been shipped out to the buyer)
    -NB is off
    -Street lights were off this morning by 6:30AM and noise still present

    -When I get home yesterday, around 4:00PM PST, I checked and things were "normal"...S5-S6 noise level on 40M (that is typical at my QTH) and nothing out of the ordinary. Regretfully, I didn't get to check 80M at that time re: the audio distortion issue. Would have been valuable information to see if that distortion is still present when the issue on 40M is not present. Something came up and I had to step away. I will check that this afternoon.

    -Left radio on 40M, did other stuff around the house. Checked again at 4:30, 5, and 5:45PM...still no issue. Still daylight here at that time.

    -Returned to the radio around 7:30PM (it is dark here at that time)...problem had returned. Terribly high noise floor with similar characteristics as to what I described in my original post. Affected range was approx. 7.088 - 7.400. S9+ noise floor across this range with "peaks" and unusual noise at (roughly) 7.088, 7.113, 7.135, 7.164, etc. Roughly 20-30k apart as I moved up the band. Below 7.088 or thereabouts, all was well.

    -Checked again this morning at 6:30AM. It is daylight at that point; noise was still there but had shifted down in frequency. Affected range was 7.020 - 7.134 and 7.239 - 7.340 approximately. Peaks and unusual noise at (roughly) 7.021, 7.048, 7.076, 7.098, etc. Again, about 20-30khz apart.

    Next steps:
    *Turn off all breakers and run radio from a car battery (may not be able to do tonight)
    *Will tune around in AM mode on 40M and report back with observations

    From what I was reading last night, it seems like grow lights/hydroponic system(s) could cause this type of issue...apparently it most commonly manifests itself on 40M and produces a high noise floor over a wide range...but it doesn't really make sense in this case, because if someone is growing MJ indoors those would be running all day and night, not just at night. My problem seems to be limited to night time only, although I've only been collecting observations for two days.

    Thanks,
    Matt
     
  10. KJ7DX

    KJ7DX Ham Member QRZ Page

    Sorry, forgot to provide an update on W1VT's comment. I did try switching to a dummy load and the noise goes away...as expected, S-meter drops to S0 and there is nothing there.
     

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