Rx wider frequency range

cmwang
Posts: 3
Joined: Sun Apr 12, 2020 6:10 am

Re: Rx wider frequency range

Post by cmwang » Sun Apr 19, 2020 6:01 am

I had no opinion for extended UHF frequency range. But I do not recommend to extend VHF frequency down to 12xMHz for following reason.

1:The civilian aeronautics use 118-137MHz in AM. Since the RDA1846 does not support AM at all,it would be meaningless to use RDA1846 to receive 12x-137MHz.

2:Support TX in 12x-137MHz in FM would be meaningless,and might cause harmful interference to civilian aeronautics.

I recommend the author could reserve extended frequency in source code,but restrict to within 136-174MHz in binary F/W to prevent unintentional abuse.

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

Re: Rx wider frequency range

Post by VK3KYY » Sun Apr 19, 2020 7:44 am

cmwang wrote:
Sun Apr 19, 2020 6:01 am
I recommend the author could reserve extended frequency in source code,but restrict to within 136-174MHz in binary F/W to prevent unintentional abuse.
The official firmware already does this range, if you change the band limits in the codeplug. Most people already did this.

User avatar
IU4LEG
Posts: 191
Joined: Wed Nov 20, 2019 12:49 pm

Re: Rx wider frequency range

Post by IU4LEG » Sun Apr 19, 2020 8:59 am

F1RMB wrote:
Sat Apr 18, 2020 2:54 pm
IU4LEG wrote:
Sat Apr 18, 2020 2:34 pm
It was also implemented the microphone gain for the FM?
Yes.

Cheers.
---
Daniel
I also tried the microphone gain in FM. works well
thanks

User avatar
F1RMB
Posts: 2518
Joined: Sat Nov 16, 2019 5:42 am
Location: Grenoble, France

Re: Rx wider frequency range

Post by F1RMB » Sun Apr 19, 2020 9:29 am

Hi,
IU4LEG wrote:
Sun Apr 19, 2020 8:59 am
F1RMB wrote:
Sat Apr 18, 2020 2:54 pm
IU4LEG wrote:
Sat Apr 18, 2020 2:34 pm
It was also implemented the microphone gain for the FM?
Yes.

Cheers.
---
Daniel
I also tried the microphone gain in FM. works well
thanks
Cool ;)


Cheers.
---
Daniel

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

Re: Rx wider frequency range

Post by VK3KYY » Sun Apr 19, 2020 10:07 am

jobdone wrote:
Sun Apr 19, 2020 9:49 am
tx on 190 made my freq counter show 380 (second harmonic)
tx on 280 made my freq counter show 560 (second harmonic)
There is no RF stage for the range from 174 - 400Mhz, but I found it was better to enable the UHF PA and the UHF Rx amp, because if I use the VHF RF sections for this range, the Rx sensitivity is low.

Its not possible with the way the firmware is written to use a different RF section for the Rx to the Tx.
And the change to make the best use of the baseband RF chip are intended for Rx.

W1CY
Posts: 76
Joined: Sun Jan 12, 2020 6:57 pm

Re: Rx wider frequency range

Post by W1CY » Mon Apr 20, 2020 6:26 am

Radio #1:

127 - 178
190 - 282
380 - 564

CX2JO
Posts: 4
Joined: Mon Apr 20, 2020 1:17 pm

Re: Rx wider frequency range

Post by CX2JO » Mon Apr 20, 2020 1:21 pm

HI.MY BAOFEN DM-1801 IN TX WORK:

136000 to 172000 - vhf
381000 to 500000 - uhf


does not work at 200 mhz, is this so? Can someone make it work in that band correctly? :cry:
73

User avatar
F1RMB
Posts: 2518
Joined: Sat Nov 16, 2019 5:42 am
Location: Grenoble, France

Re: Rx wider frequency range

Post by F1RMB » Mon Apr 20, 2020 1:35 pm

Hi,
CX2JO wrote:
Mon Apr 20, 2020 1:21 pm
HI.MY BAOFEN DM-1801 IN TX WORK:

136000 to 172000 - vhf
381000 to 500000 - uhf


does not work at 200 mhz, is this so? Can someone make it work in that band correctly? :cry:
73
Did you turned "Band Limits" off, in the Options ?

Cheers.
---
Daniel

CX2JO
Posts: 4
Joined: Mon Apr 20, 2020 1:17 pm

Re: Rx wider frequency range

Post by CX2JO » Mon Apr 20, 2020 1:54 pm

Hi,
If I verify that exactly, then I have another one that in uhf I cannot achieve that transmits in hotspot mode in uhf, I don't know if this problem has happened to someone. Do you say that in the 200mhz band in rx and tx it has the same range? and what power does it offer?
thanks
F1RMB wrote:
Mon Apr 20, 2020 1:35 pm
CX2JO wrote:
Mon Apr 20, 2020 1:21 pm
HI.MY BAOFEN DM-1801 IN TX WORK:

136000 to 172000 - vhf
381000 to 500000 - uhf


does not work at 200 mhz, is this so? Can someone make it work in that band correctly? :cry:
73
Did you turned "Band Limits" off, in the Options ?

Cheers.
---
Daniel

CX2JO
Posts: 4
Joined: Mon Apr 20, 2020 1:17 pm

Re: Rx wider frequency range

Post by CX2JO » Mon Apr 20, 2020 1:58 pm

It has installed the last fw dated 04/18/20 where the frequency expansion is, as it is in beta, I am interested in trying and seeing what errors can be corrected.
73 javier
CX2JO wrote:
Mon Apr 20, 2020 1:54 pm
Hi,
If I verify that exactly, then I have another one that in uhf I cannot achieve that transmits in hotspot mode in uhf, I don't know if this problem has happened to someone. Do you say that in the 200mhz band in rx and tx it has the same range? and what power does it offer?
thanks
F1RMB wrote:
Mon Apr 20, 2020 1:35 pm
CX2JO wrote:
Mon Apr 20, 2020 1:21 pm
HI.MY BAOFEN DM-1801 IN TX WORK:

136000 to 172000 - vhf
381000 to 500000 - uhf


does not work at 200 mhz, is this so? Can someone make it work in that band correctly? :cry:
73
Did you turned "Band Limits" off, in the Options ?

Cheers.
---
Daniel

Post Reply