ALPHA 2022 11 02

S58SMS
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Re: ALPHA 2022 11 02

Post by S58SMS » Fri Nov 04, 2022 9:59 am

OE1MWW wrote:
Fri Nov 04, 2022 8:09 am
S58SMS wrote:
Thu Nov 03, 2022 5:05 pm
Hello.

Does anybody own md380 and baofeng or gd77. I own both and did a test. Md380 has much worser rx reception than baofeng 1801 does. I did a research on uhf and vhf. On uhf it works more or less ok, but on vhf, its a really big difference. Any suggestions. Will be possible to calibrate it?

Br
My Retevis RT-3S (same as MD380, just other labels on housing) and my GD-77 - with exactly same brand & type of antenna, the RX sensitivity
on VHF & UHF is roughly the same. Consider, what can you expect from a 150 dollar (end user!) device ?
There is not much room for quality control, or to produce equal precise specifications for each device. Unfortunately... :-(

'calibration' is the term of adjusting a measurement info compared to a given standard: Example: scale/display shows 5 watt - measured output
on a calibrated watt meter is the same, if not, the display/scale must be adjusted accordingly, so it will be kind of 'calibrated' too.
Btw., I don't think sensitivity of a MD380 can be adjusted.
73's de OE1MWW
Wolfgang

I did a research, had two rt3s and baofeng1801, all low budget... baofeng has better rx, rt3s lower reception, both ones. Tried with gd77, and also worser reception. I think that opposite sma might have sth to do with the reception... idk. I will make a video and post it for a comparison.

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Fri Nov 04, 2022 10:12 am

S58SMS wrote:
Fri Nov 04, 2022 9:59 am
I did a research, had two rt3s and baofeng1801, all low budget... baofeng has better rx, rt3s lower reception, both ones. Tried with gd77, and also worser reception. I think that opposite sma might have sth to do with the reception... idk. I will make a video and post it for a comparison.
Most likely the variabilty in reception is poor manufacturing standards.

Various people have tested these radios under laboratory conditions, and Rx performance on the RT3S was measured to be the same on UHF on the GD77 and RT3S.

However, IMO the RT3S RF hardware design is inferior to both the GD77 and DM1801.

The DM1801 and GD77 (and GD77s) have virtually identical RF hardware design

The RT3S has similar RF hard design to the Baofeng RD5R

I own all these radios have have dissassembled them to study the design of the radio

All these radios use the same core RF TRx chip (AT1846S) but the RF PA and Preamp stage(s) is completely different on the RT3S and RD5R to the GD77 and DM1801
The MD9600/RT90 RF hadware is completely different to all the hand held radios

S58SMS
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Re: ALPHA 2022 11 02

Post by S58SMS » Fri Nov 04, 2022 11:00 am

Thank you for the explaination. What i did is, that i have ordered better quality antenna and i will report. Anyways it's an hardware issue, so i won't trash this thread...

BR

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VK5FSCK
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Re: ALPHA 2022 11 02

Post by VK5FSCK » Sat Nov 05, 2022 8:12 pm

VK3KYY wrote:
Wed Nov 02, 2022 7:43 am

......

The new GPS screen has 2 pages,
Page 1 shows position after GPS fix has been achived and shows bar graphs of GPS satellite RSSI
Page 2 shows polar plot the satellites, when the GPS module provides this data.

......
Looks good, but the GPS seems to be a lot slower to acquire birds compared to the previous version of firmware (2022-10-24). Not sure if this been asked yet, but is there any plans to adding APRS support?

Regards & 73
Dale de VK5ZSH

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Sat Nov 05, 2022 9:04 pm

We have no control of how long it takes for the GPS to get a fix. I posted to a separate topic about how very slow the GPS is in these radios are

I am working on DMR Tx of position in the TA data, as there seems to be a standard for this, and the firmware already decodes the location in the TA data.
However, I don't know if any networks use this data even if the radio transmits it

We do not know whether the hardware in the radio is capable of sending FM APRS tones fast enough. I.e the hardware is only designed to send DTMF at a few tones per second, but APRS requires 1200 bits per second, and the hardware may not be able to respond to the tone commands fast enough.

Also, I noticed today, the GD77 is incredibly low in remaining ROM space, so its getting to the point on that radio where addition feature can't be added. I am not sure about the UV380 and MD9600

UA0LMC
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Re: ALPHA 2022 11 02

Post by UA0LMC » Sun Nov 06, 2022 4:56 am

VK3KYY wrote:
Sat Nov 05, 2022 9:04 pm
We have no control of how long it takes for the GPS to get a fix. I posted to a separate topic about how very slow the GPS is in these radios are

I am working on DMR Tx of position in the TA data, as there seems to be a standard for this, and the firmware already decodes the location in the TA data.
However, I don't know if any networks use this data even if the radio transmits it
Excellent news!
I've been waiting for this feature, even considered adding GPS receiver to dm1801.
AFAIK, at least BM supports this - but you have to explicitly enable In-call GPS in selfcare.

VK3KYY wrote:
Sat Nov 05, 2022 9:04 pm
We do not know whether the hardware in the radio is capable of sending FM APRS tones fast enough. I.e the hardware is only designed to send DTMF at a few tones per second, but APRS requires 1200 bits per second, and the hardware may not be able to respond to the tone commands fast enough.
AFAIK, there is no direct audio path from CPU to AT1846. How exactly TX tones are generated? Does it use an internal AT1846 DTMF encoder?
A good idea is to perform something similar to OpenRTX M17 hardware mod to make FM APRS implementation less painful - but I doubt it's feasible.

VK3KYY wrote:
Sat Nov 05, 2022 9:04 pm
Also, I noticed today, the GD77 is incredibly low in remaining ROM space, so its getting to the point on that radio where addition feature can't be added. I am not sure about the UV380 and MD9600
Sad news.
Is there any chance to use an external flash not only for DMR ID database but for a part of the firmware as well?
Maybe for some non-critical parts like additional languages etc.

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Sun Nov 06, 2022 5:18 am

1. Adding a GPS receiver to a DM1801 won't work, because the OpenGD77 on the GD77/DM1801/RD5R does not have support for GPS, there is vitually no free space in ROM to add this.

You can download the last stable release source code and modify it yourself if you want to attempt this.


2. AT1846S and C6000 can both generate tones. That's how DTMF Tx works, both chips are not designed to send data at 1200 tones per second, so it may not be possible to transmit APRS

3. Its not practical to support modified hardware.

4. No CPU does not support loading code from Flash memory. I have no plans to move the fonts or the language support to Flash, because this would take a huge amount of time to write and be a support nightmare

bg3nct
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回复:阿尔法 2022 11 02

Post by bg3nct » Sun Nov 06, 2022 8:59 am

The time zone setting still doesn't work。

BG3NCT

73

VK3KYY
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Re: 回复:阿尔法 2022 11 02

Post by VK3KYY » Sun Nov 06, 2022 9:12 am

bg3nct wrote:
Sun Nov 06, 2022 8:59 am
The time zone setting still doesn't work。

BG3NCT

73
Timezone setting does work, but you must set Time:Local setting, otherwise UTC is displayed.

UA0LMC
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Re: ALPHA 2022 11 02

Post by UA0LMC » Sun Nov 06, 2022 2:00 pm

VK3KYY wrote:
Sun Nov 06, 2022 5:18 am
1. Adding a GPS receiver to a DM1801 won't work, because the OpenGD77 on the GD77/DM1801/RD5R does not have support for GPS, there is vitually no free space in ROM to add this.
It's not a problem anymore, now I have RT-3s ;)

VK3KYY wrote:
Sun Nov 06, 2022 5:18 am
3. Its not practical to support modified hardware.

4. No CPU does not support loading code from Flash memory. I have no plans to move the fonts or the language support to Flash, because this would take a huge amount of time to write and be a support nightmare
I' ve suspected this - but asked just to make sure.

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