Central Testing on 3935Khz

[Joe K]

Central radio now testing on 3935khz from NW England tonight.
TX power is 50watt, any reception reports would be appriciated.

[Johnno]

Theres a 9+40 signal on 3934 but modulation is dreadful. Can't tell if its 2 signal mixing or what.

[irishpaul]

hi joe k good signal on 3935 but noise level is high where you on 3930 @16.18 utc

73's paul

[Joe K]

Johnno and Irish Paul thanks for the reception reports, I think there may be another station on same frequency, audio sounds ok here. Yes I was on 3930khz earlier this evening. Think I might change frequency back to 3930khz to see if its a clearer frequency.
Thanks again for the reports

Joe K

[Johnno]

Hi Joe

there is something VERY wrong with the audio I'm hearing here.


Theres a noise on the carrier that sounds somewhat like a PLL thats gone wrong.... The result is a mix of the noise plus the music.

I can send an audio file if you want. Its not pretty.

[Joe K]

Hi Johnno,

I am using a homemade PLL at moment and I suppose there might be instability causing the modulation distortion! If you can send me an audio file I would be grateful it might help me work out what it is. I dont know if Irish Paul is receiving the same modulation probems.

Thanks

Joe

[iann1971]

Hello Joe,

i can only say the same things than Johnno and Irish Paul.
I heard you on 3934 and 3930, but the modulation is bad, mixed, a lot of distorsion. Your signal is about 6 here, but i can not recognize what i hear.

Greetings.

Iann

[Joe K]

Hello Iann,

Thanks for the report, it confirms what Johnno is saying. The only thing that makes sense is a problem with the transmitters PLL. I shall look into the problem, thanks again for the information.

Joe

[Johnno]

Hi Joe

I can't send a file at the moment. If you want to pm an email address, i could do it later.

I checked an online tuner and it sounds exactly the same as what I'm hearing here.

Another possibility is the tx has a parasitic oscillation problem.

For several seconds it can sound alright and then it goes bad again.

[irishpaul]

Hi joe yes i agree with johnno and iann. signal is better on 3930 but modulation is very poor
73's paul

[Joe K]

Hi Paul/Johnno,

Your comments have been very useful, I have recently built the mosfet transmitter and I think Johno you have hit the nail on the head. It does make a lot of sense when you suggest it could be parasitic oscillations! Johnno please dont bother sending the audio file I shall get to the bottom of the problem without it
.
Thanks again for the information

Cheers

Joe

[Johnno]

Grand so.

Hope you get it sorted as the signal was very good here.

[newfoundland dxer]

Very good signal here in Newfoundland, Canada.

Faded in at the ridiculously early time of 1940 on 3934, improved gradually up to 34443 by 2100 on 3930 (no significant difference between frequencies noted here).

Unfortunately, unable to distinguish any details, just warbly noise with occassional hints of music.

If this was only 50 watts, you were doing very, very well. Sort out the audio and I definitely look forward to hearing you again.

Cheers, Terry

[Joe K]

Hi Terry,

Thanks for your report, really pleased with the aerial at the moment it seems to be working ok. Shame about the TX fault but I will get it sorted out. Your rception report is the furthest I had on MW or SW which gives me extra motivation to sort things out.

Cheers for that

Joe

[eldorado]

nice to see some good activity here.

i am gonna boom in over to you ' gang '

in some days.

i have tested my modulation and it is sweet analog...

yummi.



have fun.