Hot answers tagged

15

This is the one I use for my Baofeng UV-5R.


10

Here is a Diagram from page 11 of The (Chinese) Radio Documentation Project's Baofeng UV-5R Manual PDF:


8

Here's how to repair a Kenwood MC-59 microphone cable (ships with the TM-V71a, probably the 710, and a few LMR radios as well). First, if you didn’t know already, behind the rubber boot at the end of the Kenwood MC-59 mic cable is a regular RJ-45 jack: Step 0. If you want to avoid all this, the cord is part Kenwood E30-7543-18 at PacParts.com. (They also ...


7

If you would like to decode Morse code with an existing program: My personal recommendation is Fldigi, which is a software modem that runs on most major operating systems, including Windows and Linux. Fldigi has a modem for "CW" (Continuous Wave), which can both send and receive Morse code. The program uses your sound card to communicate with your radio. To ...


7

"Tone", displayed as "T" on the main screen, selects tone encoder + carrier squelch (your HT will send a tone, selected by the TONE Freq menu, and receive any strong-enough signal, regardless of whether it has a tone.) The transmitted tone is necessary to "open up" most repeaters so that you can talk on them. "CTCSS", displayed as "CT" on the main screen, ...


6

This image of the bottom side of the bracket was taken with a flatbed scanner. The depicted dimensions were taken separately using a caliper, not by measuring on the image. The white inner area is the paper over an as-yet-unused adhesive pad; the material of the bracket is black-painted metal. Unprocessed image


6

The manual, on page 56 says: TX monitor allows you to monitor the on-going transmission sound. This is convenient when you want to check the modulation sound quality of the transmission. In FSK mode, you can monitor the FSK signal that the transceiver is transmitting. 1 Press and hold [PWR (TX MONI)]. • The current TX monitor setting appears on the sub-...


5

Hannu OH1HAQ emailed me the true correct two-step answer: Set VOX GAIN to 0: long press on VOX button, rotate MULTI knob to set the level to 0, long press on VOX button. Enable VOX. With VOX GAIN set to 0, noise picked up by the microphone will not key the transmitter. However, replaying from the voice keyer memory will still key the transmitter if VOX is ...


3

First of all, only Band A (left side) can be tuned to the aviation band; if you try to use Band B it will not work. Press the left "BAND SEL" button (volume knob). Then you should be able to use the tuning knob to tune to the frequency you want. If it skips over the aviation band, then the first thing to check is that the aviation band is not masked. This ...


3

I found the TM-741A service manual. As shown on page 106, the battery can be seen looking into the case from the front after the display panel is removed. Luckily, the spare batteries from my dive computer will work; now I just have to open the radio and solder in a replacement!


3

I found a list of specifications for the TS-480SAT giving the matching range as 16.7 Ω – 150 Ω. Another list of specifications for the TS-870SAT says that model's matching range is 20 Ω – 150 Ω. Both ranges roughly correspond to a 3:1 SWR, which is typical for antenna tuners built into transceivers. External antenna tuners generally offer more tuning ...


3

I took it apart and found a transistor that had been blown apart, pictured below (the black one with its metal innards showing), likely from a scenario described by @rclocher3. This is the NPN transistor that supplies voltage to the blue PNP transistor and should be switching based on its base input but instead is supplying a constant 5V. No surprise there, ...


2

TM-V71A firmware update Ver.2.00 (May 16, 2008) added microphone sensitivity to the Menu (No. 111) so that MCP-2A is not needed to change it.


2

Typically a good place to get discriminator audio is the "high" end of the squelch control. Unfortunately the TM-241A does not have a conventional squelch control, making it necessary to tap onto the board itself. Pin 9 of IC1, an MC3372, is the output of the discriminator. If you can locate and solder to this pin it should give you the desired signal. If ...


2

The origin of this connector is Kenwood. We work with Kenwood and build custom headsets for Kenwood. This link is pretty much up to date and definative. https://www.wildtalk.com/knowledge-base/kenwood-2-pin-wiring-data/ The 5V pin has varied over time. Initially this was via a 100 ohm limiting resistor to provide power to an external VOX unit. More recent ...


2

FWIW: The Baofeng UV-5R HT supplies 3.3V through 100(*) ohms on the tip of the 3.5mm connector, not 5V as documented above. Also, the PTT is pulled up thru 10K to 3.3V, and the MIC+ connection line also has a more complex (constant current source?) pullup to 3.3V. [This is nice, as the PTT line can directly connect to a Raspberry Pi GPIO pin!] There's a (...


2

I am setting up a B2000, a TH-D72 and a 710GA. The best practice is to set the APRS freq to 144.39 MHz in Band B then configure the data band of the TNC to B-Band. You can lock it as well. Kenwood has "In Depth" Manuals for each model for APRS.


2

Just give the knob a good flick in the direction you want to go. The radio automatically switches to 1kHz tuning when the knob is moving at a fast pace. Manual page 8, paragraph 22


2

I assume you have extensively bench tested the kit and have not found any problems. Having several years of experience with high altitude radios in the Alps, I would suspect that you are getting static build-up on the antenna that is glitching the radio. A Polyphasor, or equivalent, to ground can mitigate static build up. Failing that, a couple of megohms ...


2

The ICOM gateway terminal mode is a unique mode. It allows you to configure the radio to use the radio, tethered to a computer through a USB cable, to route the communications through the computer, out to the Internet, to access a remote gateway. In this mode, the RF signal of the radio is not a factor since all communications are actually going through the ...


2

It likely uses the external speaker output because not all rigs (especially older ones) have an RX audio output pin. And even if a rig does, it's possible that the audio output is before de-emphasis is applied so the TNC wouldn't be able to decode reliably. As Mike said, the circles represent the cable shield. As far as the microphone ground, read here: ...


2

Unless you tried to transmit without an antenna, it should be fine. If the radio is in receive mode without an antenna, it won't hurt it. But if you transmit without an antenna, especially at high power, the high SWR could damage the final amplifier in the radio.


2

According to the manual, it says "Appears while using the External data band", and all of the images of the display in the manual show it only appearing on the B band. However, menu setting (according to the manual, again) 517 allows you to set how the external TNC data band setup is defined (A band, B band, Tx on A and Rx on B, or Tx on B, Rx on A)...


2

Echolink allows repeaters to be connected over the internet, and also allows licensed hams with computers to connect to the system directly without using a radio. So there are two ways to participate: Find a local repeater that is connected to the Echolink system, and access that repeater with your radio. Download, install, and run the Echolink software on ...


2

In the keyer, PNP transistor Q4 should be on when the keyer is supposed to be keyed. I assume that the transceiver's key jack goes to a CMOS high-impedance input and has a pull-up resistor, and that the key jack's sleeve terminal is tied to ground. If all that is correct, and if the keyer is working correctly, then the positive output of the terminal ...


2

I'm not quite sure why things worked in today's testing, possibly I was just in a dead zone yesterday. Here's the setup that's working though: DRA-50 is plugged into radio's "Data" port (on main body) and into laptop. This is the port for using an external TNC, which is indicated by a plain 'D' next to the power level indicator on whichever band it'...


1

To disable Repeater AutoShift turn the power off. Press and hold both the VFO and REV keys while turning power on. Do this again to turn Autoshift back on. The manual makes mention of using the SHIFT key to override the autoshift but I am not sure how this works. I have multiples of this radio and have never had the occasion to need to use a non-standard ...


1

Use an open source software called CHIRP: http://chirp.danplanet.com/projects/chirp/wiki/Home The software will work for your radio. It is fairly universally used and not that difficult to learn.


1

AFO is filtered, squelched audio. DEO is raw discriminator audio. Here is a PDF of the NX-700 pin documentation.


Only top voted, non community-wiki answers of a minimum length are eligible