W7ML in Los Angeles

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W7ML
Posts: 84
Joined: Sat Jul 17, 2021 12:48 am
Location: Los Angeles, CA USA

W7ML in Los Angeles

Post by W7ML » Sun Jan 16, 2022 12:25 am

I've been using a RD-5R since 2018 and I am excited to use OpenGD77 with it soon!

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: W7ML in Los Angeles

Post by VK3KYY » Sun Jan 16, 2022 2:51 am

MichaelLAX wrote:
Sun Jan 16, 2022 12:25 am
I've been using a RD-5R since 2018 and I am excited to use OpenGD77 with it soon!
Be aware there are some limitations to the firmware on the RD5R. Hotspot does not work due to hardware limations and the 100Mhz band FM Rx does not work, because we have been unable to find a datasheet for that chip.
We know the part number of the 100MHz FM radio chip, but all available data sheets for that part number do not match the chip thats in this radio.

W7ML
Posts: 84
Joined: Sat Jul 17, 2021 12:48 am
Location: Los Angeles, CA USA

Re: W7ML in Los Angeles

Post by W7ML » Sun Jan 16, 2022 5:21 am

Thanks for that reply: I am advising a friend to buy the GD-77 instead of the RD-5R to avoid those limitations.

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: W7ML in Los Angeles

Post by VK3KYY » Sun Jan 16, 2022 5:28 am

W7ML wrote:
Sun Jan 16, 2022 5:21 am
Thanks for that reply: I am advising a friend to buy the GD-77 instead of the RD-5R to avoid those limitations.
Good idea

Not worth saving a few bucks.

Baofeng DM-1801 is sometimes cheaper than the GD77 and does not have the limitations as the RD-5R

oh1fss
Posts: 74
Joined: Mon May 04, 2020 11:53 am

RD-5R

Post by oh1fss » Sun Jan 16, 2022 10:56 am

VK3KYY wrote:
Sun Jan 16, 2022 2:51 am
Be aware there are some limitations to the firmware on the RD5R. Hotspot does not work due to hardware limations and the 100Mhz band FM Rx does not work, because we have been unable to find a datasheet for that chip.
We know the part number of the 100MHz FM radio chip, but all available data sheets for that part number do not match the chip thats in this radio.
I have both GD-77 and RD-5R. For my purposes both work equally well. But received audio is equally bad in both radios. :(

The RD-5R is little smaller than GD-77. RD-5R can use most UV-5R acessories.

I don't use these radios as hotspots. Instead I use a cheap MMDVM board from Aliexpress on top of a Raspberry Zero.

100 MHz FM broadcast band support would be nice.

The keys on RD-5R are different from those used in the manual, so I have downloaded a picture to my cell phone which shows the correspondence between RD-5R and GD.77 keys.

oh1fss
Posts: 74
Joined: Mon May 04, 2020 11:53 am

RD-5R power switch

Post by oh1fss » Sun Jan 16, 2022 11:14 am

Another difference between RD-5R and GD-77 is the power switch. In GD-77 the switch is "soft", so before really switching off the GD-77 software has a chance to save the current channel.

However, in RD-5R the power switch cuts the power off immediately, so the firmware does not run any more. So on RD-5R the last channel is stored more often (which caused wear on the memory chip) when you change the channel. And suspend mode is not implemented on RD-5R.

But I think that suspend mode could be implemented on RD-5R if the power "off" function were implemented as a menu option instead of by using power off switch.

http://www.opengd77.com/viewtopic.php?f ... 813#p15814

VK3KYY
Posts: 7478
Joined: Sat Nov 16, 2019 3:25 am
Location: Melbourne, Australia

Re: RD-5R power switch

Post by VK3KYY » Sun Jan 16, 2022 8:19 pm

oh1fss wrote:
Sun Jan 16, 2022 11:14 am
Another difference between RD-5R and GD-77 is the power switch. In GD-77 the switch is "soft", so before really switching off the GD-77 software has a chance to save the current channel.

However, in RD-5R the power switch cuts the power off immediately, so the firmware does not run any more. So on RD-5R the last channel is stored more often (which caused wear on the memory chip) when you change the channel. And suspend mode is not implemented on RD-5R.

But I think that suspend mode could be implemented on RD-5R if the power "off" function were implemented as a menu option instead of by using power off switch.

http://www.opengd77.com/viewtopic.php?f ... 813#p15814
Its not possible to implement suspend mode on the RD5R, because there would be no battery protection.

If the operator enabled suspend mode, and then forgot they did this, the battery would be drained completely in about 2 days , and the battery would then be destroyed.

I know that the operator could leave the radio turned on, and flatten the battery, but in that case the display continues to be shown and also hence the operator can see they did not turn off the radio.

W6PGC
Posts: 3
Joined: Thu Jul 14, 2022 1:52 pm

Re: RD-5R

Post by W6PGC » Thu Jul 14, 2022 1:57 pm

You mention you have a picture which corresponds the RD5R key setup to the key setup for the GD77, could you share that with me/us?
oh1fss wrote:
Sun Jan 16, 2022 10:56 am
I have both GD-77 and RD-5R. For my purposes both work equally well. But received audio is equally bad in both radios. :(

The RD-5R is little smaller than GD-77. RD-5R can use most UV-5R acessories.

I don't use these radios as hotspots. Instead I use a cheap MMDVM board from Aliexpress on top of a Raspberry Zero.

100 MHz FM broadcast band support would be nice.

The keys on RD-5R are different from those used in the manual, so I have downloaded a picture to my cell phone which shows the correspondence between RD-5R and GD.77 keys.
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