We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: 6393 AM 19.42 UTC 23 Sep 2017 R.NOVA Int. unexpected modulation  (Read 2264 times)

Offline kris

  • Marconi Class DXer
  • ********
  • Posts: 7741
  • N.Poland
    • View Profile
    • Email
19.42 UTC music on 6393 AM mostly narrow modulation without carrier.
USB and LSB not readable  ::)

S6 Utwente WEB SDR NL
« Last Edit: September 27, 2017, 2346 UTC by kris »
RX888 ( SDR-FE-PLAY, HRD-747, Sony XDR-F1HD),
Ant. Sky Loop 180m 15m AGL, Sky Loop 120m 35m AGL
       + QRM X-phase eliminator
QTH: Gdańsk N.Poland  Ru/Sp/Gr/Sb=Russian,Spanish,Greek,Serbien
eQSL appreciated to: 13krzycho@gmail.com

Offline Clutter Free

  • Newbie
  • *
  • Posts: 10
  • Space
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #1 on: September 23, 2017, 2219 UTC »
19.42 UTC music on 6393 AM mostly narrow modulation without carrier.
USB and LSB not readable  ::)

S6 Utwente WEB SDR NL

10 watts from Ireland.

Think i mentioned before it is a xtal controlled tx, xtal cut for 6400 with a cap and inductor thrown in to pull it down in frequency and once its pulled away from 6400, well you have heard it lol..

Apparently the inductor in the xtal circuit is picking up RF and causing havoc with the oscillator so solutions are, chop out the inductor and stick to 6400 or find other xtals. Ebay has the chunky FT-243 type in suitable freqs for the tx but if anyone on here knows or has one or two knocking around let me know.

Cheers.

Online Ray Lalleu

  • Moderator
  • Marconi Class DXer
  • *****
  • Posts: 32893
  • Western part of France
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #2 on: September 23, 2017, 2320 UTC »
Heard in W. France at 1902-2102 UTC, on 6394 approx.

heard very often on those last days, on 6400 approx., always with strange mod to say the least,
with more audio in the lower side band, fuzzy carrier, no or almost no upper side band,
already not easy to get audio, but now there is a slow Morse signal on 6398,5 (probably the "Common & precious II" reported elsewhere, I'm just thinking to something else for the name!).

Today, better audio, details:
1951 Baby you're no good
2053 Mythical woman
2101 jingle ID from Radio NOVA

Ray

PS. If your inductor was winded wound on a small ferrite ring core, maybe there would be less HF pickup

« Last Edit: September 24, 2017, 2141 UTC by Ray Lalleu »
D/E/F/G/It/Sp : Dutch/English/French/German/Italian/Spanish
+/- : about 0.02 offset, ++/-- 0.03/0.04 offset
Balanced wire antennas, wire lines and ATU

Offline Clutter Free

  • Newbie
  • *
  • Posts: 10
  • Space
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #3 on: September 23, 2017, 2354 UTC »
Heard in W. France at 1902-2102 UTC, on 6394 approx.

heard very often on those last days, on 6400 approx., always with strange mod to say the least,
with more audio in the lower side band, fuzzy carrier, no or almost no upper side band,
already not easy to get audio, but now there is a slow Morse signal on 6398,5 (probably the "Common & precious II" reported elsewhere, I'm just thinking to something else for the name!).

Today, better audio, details:
1951 Baby you're no good
2053 Mythical woman
2101 jingle ID from Radio NOVA

Ray

PS. If your inductor was winded on a small ferrite ring core, maybe there would be less HF pickup



Cheers for the report.

Yes i had it on 6400, as you know its almost 100% when tuned there, almost. Actually it will pull down to 6375 or more but it is terrible when shifted that far..Yes its like it throws everything into the lower side band..Bizarre.

That morse is quite close and strong it swamps my little 10 watts, also with conditions the way they are, 50Kw on 6400 from Korea is doing quite a good job of wiping me out also..hence the reluctant move to 6394 ish.

Thanks for the input Ray, i will pop it on the bench as they say tomorrow. Despite the issue it has, it is quite a rugged little tx i have to say and runs quite cool for 50 watts PEP.

Cheers again.




Online Ray Lalleu

  • Moderator
  • Marconi Class DXer
  • *****
  • Posts: 32893
  • Western part of France
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #4 on: September 24, 2017, 2211 UTC »
Hello Clutter Free,

The Morse beacon on 6398.5 is much more annoying than the N.Korean station, because it is allways there.

Your small TX seems to be quite efficient when the carrier settles somewhere instead of moving with audio level. It would be worth looking hard for crystals on clear frequencies. All of the mod on the lower sideband is just something not to forget when looking for free frequencies.

73s

Ray

PS. Heard anew on Sunday morning and evening, around 6400,3 kHz (a bit farther away from the beacon)


D/E/F/G/It/Sp : Dutch/English/French/German/Italian/Spanish
+/- : about 0.02 offset, ++/-- 0.03/0.04 offset
Balanced wire antennas, wire lines and ATU

Offline Clutter Free

  • Newbie
  • *
  • Posts: 10
  • Space
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #5 on: September 25, 2017, 1933 UTC »
Hi Ray.

Yes that beacon, i am hearing it in my sleep lol.

It is quite an efficient little rig, more than happy with the rf output side of it. I plan to take it off air this evening as I have discovered another issue that may be contributing to the carrier shifting with the modulation, and the strong lower sidreband so looking forward to sorting it out.

Crystals are a plenty out there in FT-243 style, i was surprised to see so many on the frequencies I am looking for so have ordered a few to start with to give me some sort of option other than 6400!

Yes, 6400.3, had it up as far as 6400.5, a massive swing..lol..

Thanks for the report again Ray.

73's

Cheers

Offline kris

  • Marconi Class DXer
  • ********
  • Posts: 7741
  • N.Poland
    • View Profile
    • Email
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #6 on: September 25, 2017, 2120 UTC »
Today 25 Sep 6400 AM  the same mod, better receiving .
20.33 UTC  Oxygen
21.06 closedown

22.10 regular AM mod - Korean music

 73's Clutter
« Last Edit: September 25, 2017, 2224 UTC by kris »
RX888 ( SDR-FE-PLAY, HRD-747, Sony XDR-F1HD),
Ant. Sky Loop 180m 15m AGL, Sky Loop 120m 35m AGL
       + QRM X-phase eliminator
QTH: Gdańsk N.Poland  Ru/Sp/Gr/Sb=Russian,Spanish,Greek,Serbien
eQSL appreciated to: 13krzycho@gmail.com

Offline Clutter Free

  • Newbie
  • *
  • Posts: 10
  • Space
    • View Profile
Re: 6393 AM 19.42 UTC 23 Sep 2017 UNID unexpected modulation
« Reply #7 on: September 25, 2017, 2318 UTC »
Today 25 Sep 6400 AM  the same mod, better receiving .
20.33 UTC  Oxygen
21.06 closedown

22.10 regular AM mod - Korean music

 73's Clutter

Hi Kris.

You are 100%. I shut the tx down for repairs.

Listen out tomorrow, should be better  :)

Thanks for the report.

73's

 

HFUnderground T-Shirt
HFUnderground T-Shirt
by MitchellTimeDesigns