Search found 834 matches

by Daniel Wee
Mon 18 Jan 18 2021 2:05 pm
Forum: Radios
Topic: Daiwa SS-330W SMPS
Replies: 0
Views: 22

Daiwa SS-330W SMPS

30A, approx. 5-15V - SMPS
Much less noise that the existing SS-301X.

Be sure to make the modification for 220-240V operation before powering up. The fuse should also be changed to a 4A fuse.
SS-330W schematics.png
SS-330W schematics.png (3.62 MiB) Viewed 22 times
by Daniel Wee
Tue 12 Jan 12 2021 7:27 pm
Forum: Radios
Topic: Retevis RT-95 VHF/UHF
Replies: 3
Views: 1448

Re: Retevis RT-95 VHF/UHF

Attempting to use USB tethering through an Android phone to the rock64 board. The connection needs to be made and then USB tethering can be enabled on the phone. Note that a reset of either the phone or the rock64 board will turn this off and requires manually re-enabling. In order for the usb0 inte...
by Daniel Wee
Tue 12 Jan 12 2021 12:22 am
Forum: Radios
Topic: Retevis RT-95 VHF/UHF
Replies: 3
Views: 1448

Re: Retevis RT-95 VHF/UHF

USB sound card used is a Vention VAB-S13&VAB-S17 sound card, based on the HS-100B chip.
AKERS19112586tEH.jpg
AKERS19112586tEH.jpg (10.28 KiB) Viewed 1412 times
This enumerates as plughw:0 in linux.
by Daniel Wee
Tue 12 Jan 12 2021 12:16 am
Forum: Radios
Topic: Retevis RT-95 VHF/UHF
Replies: 3
Views: 1448

Re: Retevis RT-95 VHF/UHF

Based on what we built, the RT-95 should be set to output audio on the hand mic:-

(1) FUNC -> (16) SPK -> HAND (or M&H)

VOL is 8
SQL is OFF
CDT is OFF
BND is W


On the Rock64, alsamixer has the CAPTURE level set to 76.
20210111_225836.jpg
20210111_225836.jpg (2.76 MiB) Viewed 1413 times
20210111_222949.jpg
20210111_222949.jpg (2.58 MiB) Viewed 1413 times
20210111_222934.jpg
20210111_222934.jpg (2.4 MiB) Viewed 1413 times
by Daniel Wee
Mon 11 Jan 11 2021 10:52 am
Forum: Licensing and Regulations
Topic: Radio Amateur Examination
Replies: 1
Views: 808

Re: Radio Amateur Examination

Additionally - there are a number of useful sources that can help you prepare for the more technical parts of the exam.

https://slideplayer.com/slide/15334207/
https://hamstudy.org/
https://rsgb.org/main/clubs-training/tr ... ock-exams/
by Daniel Wee
Mon 11 Jan 11 2021 10:49 am
Forum: Licensing and Regulations
Topic: Radio Amateur Examination
Replies: 1
Views: 808

Radio Amateur Examination

For those wishing to get their amateur radio license in Singapore, you will need to take the Radio Amateur Examination (RAE). There are two classes, Restricted and General. The following are some material that you can use to familiarize yourself with for the tests. https://www.sarts.org.sg/on-line-r...
by Daniel Wee
Fri 08 Jan 08 2021 11:33 am
Forum: General Discussions
Topic: Packet Radio (AX.25)
Replies: 5
Views: 1294

Re: Packet Radio (AX.25)

For rock64, you need to either enable AX.25 support in the Linux kernel or compile the modules. These instructions should work:- http://k4gbb.us/docs/raspberry.html For the autogen to work, you also need to install automake and the ncursesw library:- sudo apt install automake libncursesw5-dev AX.25 ...
by Daniel Wee
Wed 06 Jan 06 2021 10:25 pm
Forum: General Discussions
Topic: SARTS Repeaters
Replies: 6
Views: 1065

Re: SARTS Repeaters

Measurements of the repeater cavity shows that it is very likely detuned and will require re-tuning of at least one of the receive notches and one of the transmit notches. Of the four, only two are correctly tuned at the moment. S11loss-9V1cavity-6Jan.png VSWR-9V1-6Jan.png The markers are as follows...
by Daniel Wee
Tue 05 Jan 05 2021 9:27 pm
Forum: General Discussions
Topic: Packet Radio (AX.25)
Replies: 5
Views: 1294

Re: Packet Radio (AX.25)

In order to get Direwolf working with the rock64 SBC, we will need to figure out the appropriate GPIO pins to use for activating the PTT. The GPIO pin numbers are going to be different from that of the Raspberry Pi. The mapping for the 40-pin header is as follows:- rock64-GPIO-map.jpg More info can ...