Scan speed versus sensitivity

VK3KYY
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Re: Scan speed versus sensitivity

Post by VK3KYY » Thu Mar 25, 2021 9:36 pm

I'm still not sure what to call this setting.

I think

Scan speed

would also fit, as would

Scan dwell


There is only space for a 5 letter word to describe this setting, which is a bit limiting, but in English we have several options

I think technically 'dwell' is possibly the most accurate, but possibly its less understandable that either 'speed' or 'step'
'step' is used in the VFO for the frequency step, but I guess 'step' can refer to many different things.

G4EML
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Re: Scan speed versus sensitivity

Post by G4EML » Fri Mar 26, 2021 12:23 am

Scan speed is the common term used in many radios.
Ideally the setting would then be in channels per second rather than time per channel.
Larger number = faster scan.

VK3KYY
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Re: Scan speed versus sensitivity

Post by VK3KYY » Fri Mar 26, 2021 12:33 am

G4EML wrote:
Fri Mar 26, 2021 12:23 am
Scan speed is the common term used in many radios.
Ideally the setting would be in channels per second rather than time per channel.
We could change to channels per second, and drop the units.

But the default is 1000 / 30 ms = 33
And the next step of 60ms would be 16, then 11 then 8

Which may look a bit odd.

I'm trying to limit the storage taken by this data, and was only using 4 bits, hence the max value of 480 = 16 * 30

To change to channels per second, we'd probably need to start at 30 and dwell on each channel for 33 ms

However, personally I quite like the step time in milliseconds as it looks a bit more technical than the channels per second number.

VK3KYY
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Re: Scan speed versus sensitivity

Post by VK3KYY » Fri Mar 26, 2021 12:48 am

I'm also wondering whether I should make scanning work with the power saving / eco mode

Scanning will however be a lot slower, the time on each channel would be the duty cycle time for the eco mode, and even on eco level 1 this is nearly 400 milliseconds

So the scan rate would only be about 2 channels per second.

Currently the Eco Modes are set to pretty much guarantee that if there is a signal, it will be detected in one cycle of the power saving, to give reasonable latency.

I guess I could use the scan step time for the eco mode Rx "On" time, but it would probably get very confusing, to operators because the scan speed would depend on whether the radio entered power saving or not.

ok1pt
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Re: Scan speed versus sensitivity

Post by ok1pt » Fri Mar 26, 2021 3:40 am

Hi Roger!
I believe that scan speed (in ms) is the best, it's technically clear and fequently used.
Regardign scan vs. Eco, I would recommend automatically disable Eco during scan. Scanning 2 channels per second is really suboptimal, as having for example 20 channels to scan will make one round per 10 seconds, which is a really weak performance :-). Or, let's do it like this: In Eco 0, let the user to select scan speed. In any other Eco mode, Scan speed will show "Eco" and no choice to select, so the users will understand why the scan speed is so slow and why they cannot change it and they will disable Eco mode if they want to scan effectively. But it would be fine to remember the numerical setting (made first with disabled Eco) in the background and if the user disables Eco again, the remembered Scan speed value returns back.
With regards,
Pavel

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Re: Scan speed versus sensitivity

Post by VK3KYY » Fri Mar 26, 2021 4:03 am

ok1pt wrote:
Fri Mar 26, 2021 3:40 am
Hi Roger!
I believe that scan speed (in ms) is the best, it's technically clear and fequently used.
Regardign scan vs. Eco, I would recommend automatically disable Eco during scan. Scanning 2 channels per second is really suboptimal, as having for example 20 channels to scan will make one round per 10 seconds, which is a really weak performance :-). Or, let's do it like this: In Eco 0, let the user to select scan speed. In any other Eco mode, Scan speed will show "Eco" and no choice to select, so the users will understand why the scan speed is so slow and why they cannot change it and they will disable Eco mode if they want to scan effectively. But it would be fine to remember the numerical setting (made first with disabled Eco) in the background and if the user disables Eco again, the remembered Scan speed value returns back.
With regards,
Pavel
At the moment the radio does not enter power saving in its normal scanning modes.

The version where I added the speed control, also has some other changes which allow VFO Dual Watch to operate in power saving.
But the Eco level is reduced by 1 (if Eco level > 1), so that the latency is the same as for a normal channel.
Hence for Dual Watch its OK as there is no increase in Latency, but to have a useful scan during power saving would require a lot of changes to the power saving, and is probably not worth the effort when I know there are other bugs that need to be fixed.

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W1AEX
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Re: Scan speed versus sensitivity

Post by W1AEX » Fri Mar 26, 2021 4:49 pm

Hi Roger,

After doing separate sessions of FM scanning and DMR scanning I can see that both of my GD77 radios scan stop reliably on the first pass with a setting of 90ms. That being said, after watching them closely they do a really good job at 60 ms and 30ms too with very few instances where they don't catch the signal on the first pass. I can see where I will probably use 30ms or 60ms when scanning my larger zone configurations but will drop back to 90ms while scanning smaller zone configurations, especially with DMR.

I would agree with the previous posters that "scan speed" is the best label for this feature as it seems to be used frequently with scanner radio specs. Using increments of "ms" to indicate the sampling time on a channel is fine with me. I have also seen "cps" to indicate channels per second but I think either way should work well for our user base.

For my uses the battery consumption during scanning seems very reasonable to me so the lack of ECO savings during scans is not an issue for me. Seems like a LOT of work to venture into implementing the ECO feature during scans!

Thanks again and 73,

Rob W1AEX

kt4lh
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Re: Scan speed versus sensitivity

Post by kt4lh » Fri Mar 26, 2021 7:09 pm

Roger,

Just my two cents.. Speed doesn't really fit, as we're really talking how much time between scanning. Delay to me feels easier to understand than Dwell, but either feel more technically correct as the wording to describe how long it waits for a signal.

G4EML
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Re: Scan speed versus sensitivity

Post by G4EML » Fri Mar 26, 2021 8:56 pm

Delay and dwell to me sound more like terms for when the scan finds a signal. Speed makes the most sense but the setting then really needs to be in channels per second. It doesn’t need to be accurate. Just round the values up or down to sensible sounding numbers or use an arbitrary 1-10 with 1 as the slowest and 10 as the fastest.

Nat
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Re: Scan speed versus sensitivity

Post by Nat » Fri Mar 26, 2021 9:09 pm

Hi all,

I vote for Dwell, mS.

Nat

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