For Any HDSDR Users

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Robert11
Posts: 81
Joined: Fri Sep 28, 2018 12:00 pm

For Any HDSDR Users

Post by Robert11 » Fri Apr 05, 2019 10:30 am

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

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DanubeBCL
Posts: 203
Joined: Sat Jul 02, 2016 12:39 pm

Re: For Any HDSDR Users

Post by DanubeBCL » Fri Apr 05, 2019 11:06 am

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

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Mike2459
Posts: 318
Joined: Mon Jul 24, 2017 8:24 pm

Re: For Any HDSDR Users

Post by Mike2459 » Fri Apr 05, 2019 6:33 pm

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.

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Robert11
Posts: 81
Joined: Fri Sep 28, 2018 12:00 pm

Thanks, And Another HDSDR Question: Re: For Any HDSDR Users

Post by Robert11 » Fri Apr 05, 2019 7:06 pm

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

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Spencer887
Posts: 1
Joined: Thu Apr 18, 2019 6:35 am

Re: For Any HDSDR Users

Post by Spencer887 » Thu Apr 18, 2019 6:36 am

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
Last edited by Spencer887 on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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g1hbe
Posts: 494
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire, UK

Re: For Any HDSDR Users

Post by g1hbe » Thu Apr 18, 2019 12:22 pm

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.

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Andy

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