Page 1 of 1
For Any HDSDR Users
Posted: Fri Apr 05, 2019 10:30 am
by Robert11
Hi,
Have HDSDR up and running, but will probably use SDRUno mostly, once i figure it out.
Lots to learn.
Anyway, question for HDSDR users:
It seems very often, but not all the time, the last three digits (hundreds) on the frequency tuning display
keep re-cycling a few hundred digits over and over.
e.g, if I have: 1.762.700 entered, am doing nothing, the 700 keeps cycling to perhaps 400 and then back continuously.
Can't seem to stop it from doing this.
Any idea what is happening ?
Thanks,
Bob
Re: For Any HDSDR Users
Posted: Fri Apr 05, 2019 11:06 am
by DanubeBCL
It seems that you have "AFC" on. AFC tries to follow the carrier of an AM signal. When the carrier fades the AFC sometimes snaps to the closest frequencies of the modulated audio spectrum. Then the frequency jumps back and forth between audio frequencies until the carrier in the middle is strong enough again.
Turn AFC off if this behaviour is unwanted.
73s, Heinrich
Re: For Any HDSDR Users
Posted: Fri Apr 05, 2019 6:33 pm
by Mike2459
From my experience with HDSDR this problem only occurs in ECSS mode. Any time ECSS is selected it starts with AFC on. If you turn off AFC and later close HDSDR while in ECSS mode, the next time HDSDR is started it will start up in ECSS mode with AFC on. AFC on is apparently the default startup setting for ECSS.
Thanks, And Another HDSDR Question: Re: For Any HDSDR Users
Posted: Fri Apr 05, 2019 7:06 pm
by Robert11
Hi,
Quick thanks for info.
Would never have figured it out myself.
Hate to show my ignorance, but I guess that's the best way of learning.
Nice of you folks to take the time to help me out.
Might I please also ask this, as I realize that i don't
have a really good understanding of:
The digits that are settable above the TUNE digit line, such as: LO "A"
What is its exact purpose ?
How should one adjust this ?
How should it be relative to the TUNE Freq. that one really wants to listen to ?
What the "LO" ? What's the "A" ?
etc., etc....
Much thanks,
Bob
Re: For Any HDSDR Users
Posted: Thu Apr 18, 2019 6:36 am
by Spencer887
It seems that you have "AFC" on. AFC tries to follow the carrier of an AM signal. When the carrier fades the AFC sometimes snaps to the closest frequencies of the modulated audio spectrum. Then the frequency jumps back and forth between audio frequencies until the carrier in the middle is strong enough again. mobdro
Re: For Any HDSDR Users
Posted: Thu Apr 18, 2019 12:22 pm
by g1hbe
Bob - the LO frequency is the Local Oscillator, and it produces the central spike when you are using 'Zero IF' mode. IIRC, with HDSDR there will always be an offset between the LO and the 'listening' frequency, as any attempt to listen on the LO frequency will cause distortion.
The 'A' simply means you are using the A VFO, as opposed to the 'B' one. Having two VFO's means it's easy to jump between two frequencies.