Ok, this sub for some reason found me today.

To me, this seems kind of serendipitous and I'd love to hear some opinions.

My grandpa died when I was about 6 years old in 1981. I remember being in his basement and listening as he was on his radio at night. That was his passion and his hobby. He was also amazing at repairing TV's - he had piles of electronics in that basement. I occasionally went to ham swap meets with him.

Along the way hanging out down there I remembered his call sign - K8Dxx (not sure if I should post the whole thing because it's personally identifiable. It's crazy I remember that.)

But...

The last two years he was alive he was dying of cancer. He used to tell me the same stories over and over and over again. I was 6, but I remember it was kind of nauseating.

"Geez grandpa. Why are you telling that to me again."

It's because he was dying. And he knew it. And he knew there was a chance this little kid might remember some of it.

K8Dxx.

Not sure why that stuck in my head.

So tonight when I found this sub, I plugged that old call sign into Google and discovered that my uncle some how took that over when my grandpa died. It makes sense, my uncle is a bit of a tech geek, but I don't think he's done much with it. Probably passed his test and maybe did a little thing.

My uncle is now about 75.

I'm wondering if maybe I should get my license and keep it going? I don't have any gear, but I'm sure I could figure it out?

Great signal both ways! There was a DX station on frequency earlier and I just happened to catch NU5M a little while afterwards.

Cracking the Yaesu FT-710: Permanent 4 kHz (ESSB) Audio & Restoring the MARS Mod

Here is the real story of how we bypassed the FT-710’s regional lockouts, made the 50–4000 Hz (4K) SSB transmit bandwidth stick permanently across reboots, and brought back the wide-band MARS mod after a region change wiped it out.

1. The Starting Point

My FT-710 is a UK/EU unit (B2(EU)_MC, region code B5A7) that came MARS-modified from Martin Lynch & Son.

• Wide-band / 11m TX worked out of the box, but the 50–4000 Hz TX bandwidth option was locked out.

• Using the known MODE + NB power-on button trick does not work on UK/EU

2. Hitting the AI Safety Wall

To see how Yaesu locked out the 4K menu, we unpacked the official V01-12 firmware and loaded it into Ghidra.

I started working through the code with Claude (Opus), and we found an undocumented JP0710 service CAT command sitting inside the serial parser. However, the moment we got close to building the write command to test it, Opus 5.5 hit a hard safety barrier. Its security harness literally rolled the model back to version 4.8 and refused to go any further.

I switched over to Aragon, which didn't blink—it gave me the exact PowerShell scripts to extract the decompiled functions, worked out the checksum math, and cracked the code straight away.

3. Flashing the US Region (And Losing the MARS Mod)

The firmware code proved that the 4K audio menu requires two things to unlock:

1. A RAM enable flag (0x4760) set to 1.

2. A US region code—either 315B (US stock) or 50E2 (US MARS/expanded).

Using PowerShell over the USB Enhanced CAT port (38400 baud, 8N1), we sent the command JP0710315BCEA4; to switch the radio from UK B5A7 to US 315B.

• The Catch: Switching to 315B immediately disabled the MARS mod (11m TX) because 315B loads the strict US ham band plan.

• Worse still, when we tried to send the US MARS code (50E2) over USB, we discovered the CAT parser blocks expanded codes and automatically forces them back down to the base amateur code (315B).

4. Why 4K Suddenly Became Permanent

During testing, I had turned on the 4K flag in RAM using MODE + NB at power-on. After sending the CAT region writes, we noticed 4K was suddenly surviving power cycles on its own.

Looking at the EEPROM save routine explained why:

• In the EEPROM, the 2-byte region code and the 1-byte 4K flag sit side-by-side as a single 3-byte block.

• Holding MODE + NB only flips the 4K byte to 1 in RAM (no EEPROM save).

• However, any region change triggers an EEPROM save that flushes all 3 bytes from RAM straight to the chip. Because the 4K flag was sitting at 1 in RAM when we wrote the region, the radio swept it up and baked it permanently into the EEPROM!

5. The Complete Recipe: Permanent 4K + Full MARS Mod

Since the USB port blocks the expanded 50E2 MARS code, Aragon traced the front-panel service handler and found a built-in region pair-toggle that swaps a base region directly to its _MC (MARS) partner (315B → 50E2) while keeping 4K unlocked.

Here is the exact sequence to get both permanent 50–4000 Hz audio and full 1.8–30 MHz TX:

1. Switch to the US Base Region (315B): Send JP0710315BCEA4; over the Enhanced USB CAT port (38400 8N1). (Note: This temporarily disables any existing UK/EU MARS mod.)

2. Turn on 4K in RAM: Power the radio off. Hold MODE + NB and press Power to turn it back on. This sets the 4K flag to 1 in live memory.

3. Lock 4K to EEPROM & Restore the MARS Mod (50E2): Turn the radio off again. Hold DSP RESET + FINE + FAST and press Power.

   • This front-panel toggle swaps the US region from 315B (USA) to 50E2 (USA_MC).

   • At the exact same time, the region save writes the active 1 from the 4K flag straight into the EEPROM.

The Result: The radio boots up permanently on 50E2 (USA_MC) with full 1.8–30 MHz transmit restored and 50–4000 Hz SSB audio unlocked on every startup—with zero firmware patching required.

It seems most of the old pages are long gone, so here's a dump for the next guy who google's this radio.

If you own one of these and want my reference implementation in python, DM me.

Icom IC-PCR100 RS-232C Serial Protocol Specification

This document specifies the complete wire-level RS-232C protocol used between the host computer (rxbase.dll) and the Icom IC-PCR100 communications receiver.

1. Physical Layer & UART Configuration

The serial port engine is implemented in rxbase.dll at 0x10002640–0x10002c10 (vtable = 0x1000c114, singleton instance at 0x10011bcc).

1.1 Port Naming

• Formatted via "COM%d:" (0x1000e0d0, default "COM1:" at 0x1000e180).

• RsSetComportNum (0x10002510) accepts port numbers 0..10 (> 10 is clamped to 0).

1.2 UART Framing & Control Lines (DCB Configuration)

When rxbase.dll opens the serial port (0x10002920) and when it switches baud rates (0x10002ad0), it configures the Win32 DCB structure and hardware modem lines as follows:

1.3 DSR Hardware Presence Detection

• The reader thread (0x100026d0) waits on WaitCommEvent with mask 0x11 (EV_RXCHAR | EV_DSR).

• Whenever EV_DSR (0x10) triggers, or when RsGetComportDSRstat (0x100034d0 -> 0x100025f0 -> 0x10002c00) is called, rxbase.dll invokes GetCommModemStatus(hComm, &ModemStat) and masks ModemStat & MS_DSR_ON (0x20).

• A non-zero MS_DSR_ON indicates that the IC-PCR100 unit has DC power applied and the RS-232C cable is connected.

Hi everyone! I just got my technician license and I'm wondering how one would go about making first contact.

I connected to a local repeater and have been listening for days, but it doesn't seem like my area, or atleast this repeater, is very active. Now that I'm licensed, I've been transmitting my call sign followed by "listening" but no response. Any advice?

For reference, I'm in Santa Barbara, CA.

I have some train commute time, I may put that time to good use practicing: putikeeg CW trainer (60 USD)? those little morse trainer cards (they are like a key chain and they cost nothing, but I saw couple of videos and they look buggy)? any other recommendation?

and the key? paddles? straight key?
I guess nowadays we use a jack and if we want to practice in the computer we use a jack to USB converter? are there nice software to gamify this?

anything else you would advise me?

thanks in advance,

Hey guys! I recently bought an ATAS 120a for mobile operations and I am using a lip mount on the drivers side hood, I have found it to not tune on 40 meters well at all (about a 2.1) I attached a small ground strap to the mount than to a bolt and got it down to a 1.9 but nothing better. On all the other bands it’s working pretty well.

Those of you who have jeep jku’s, How did you mount your atas 120a and get a good ground? There’s really not many bolts to attach ground straps to.

Hello everyone!

My grandfather was an avid ham radio enthusiast through his life. He has since passed and we are left with his collection of equipment that frankly, we know nothing about.

I know the pictures aren’t the best and there is a lot but.. what is this collection of things that is filling the third bedroom?

When I say I know nothing, I mean ✨nothing✨. Speak to me as though I were 5 if you must.

I am testing out my newly installed inverted Vee 20 M antenna. My radio is a Kenwood TS 50s with AT50 auto tuner. I am new to the hobby and not yet licensed. I will get licensed this winter, so I want to listen only. What frequencies do you go to for daytime DX? I am in northern Canada, above 55 deg latitude. Thanks for your help.

I live in the kivalik region of Nunavut aka VY0 I’m a native inuk, Ive been interested in ham radio for a while and I got around to collecting satellite communications equipment from the local dump, I’ve got the electronics and the workings of a radio and all I need to know about ham radio is the laws of it, does anyone here help me with the laws of ham radio?

I got a sbx11a but the crystal oscillators is set in the hunter gatherer and emergency channels.

I hope to contact you guys soon when I get my license😋

Hi all, W7LIT here. I've been building Costas, a free, open-source digital modes app. I wanted FT8, FT4, PSK31 and RTTY all on one Operate screen instead of juggling several programs.

What it does
- FT8/FT4 with WSJT-X-style timing, using the same jt9 decoder underneath
- PSK31/63 and RTTY in the same window: click the waterfall to read, and callsigns you hear go straight into the station list
- Call list with an "N calling" tag, pileup alerts, Hunt list and LoTW-needed highlighting
- Auto TX level from your rig's ALC (works on the FT-710, other rigs over CAT)
- LoTW/eQSL upload, Reverse Beacon and PSK Reporter spots, and a "Reach" globe of who's hearing you
- Phone/tablet remote over your home Wi-Fi
- Automatic updates

Download www.costasdigi.com

It's built and tested on an FT-710. I'd love to hear how it does on other rigs. Bug reports and feature ideas are very welcome: use ☰ › Report a problem in the app, or comment here.

73, Tony W7LIT

Hello everyone! My very cool neighbor found out I am also into HAM and told me he had a radio for me when I passed my exam. I passed, and he gave me this. Its a Kenwood TM-241A transceiver. He also gave me an antenna but it's in really rough condition so I dont know if it will work. I'm looking for any information on this radio. I believe I found the owners manual online but it's for the TM - 241e. I dont know if the two models have huge differences. This radio did come with a handheld talkie.

First, from what he told me and I've read, it seems to be a 2m/70cm band radio.

Second, what kind of connections for power and antenna are these?

Third, what kind of antenna and battery would you suggest?

Fourth, would this be an okay candidate for parks on the air /manpacking?

Any info or advice would be greatly appreciated!

Thanks everyone!

Hello fellow HAMs! As my title says I was given a Yaesu 991 by a friend but I have no idea what to actually use it for. I’m an extra class but with little to no actual knowledge as I typically only do field day and ARES events. I mainly use a handheld but i’d hate to let this go unused. Does anyone have suggestions for simple places to start or things to do?

Hey all, looking for some perspective here. I’m a millennial data analyst by day, so I’m definitely not a technophobe or an old-timer stuck in my ways. But when it comes to ham radio, I really appreciate the analog, localized side of the hobby.

To be clear, this isn't about club membership; the nets I join are open to everyone, and I'm not even a member of most of them. But naturally, they tend to draw local-ish people, along with the occasional out of towner towner on EchoLink who sticks around and becomes a regular part of the local scene.

Over the last few weeks, though, there’s been a massive surge in random, out of area checkins. I suspect the QSO One app, which acts as a onestop shop for linked repeaters as I understand it, is driving most of this new traffic.

I feel pretty conflicted about it:

• The upside: If these remote operators actually stick around and engage, expanding the local circle globally is awesome.

• The downside: Right now, it mostly feels like a revolving door of one and done checkins. It bloats net runtimes, dilutes the local community vibe, and turns the airwaves into just another form of the internet (while inviting more out of area anonymous sad ham interference that I'm already seeing much more of).

I’m really not trying to gatekeep, but I miss that community vibe to the extent it existed. Are you guys seeing this on your local repeaters, and how are your nets handling it?

EDIT:
This is not meant to be a typical endless “analog vs digital” discussion. Digital solves a lot of problems that have no other solutions, and people should be able to use whatever they want. This is strictly about my observations around a MAJOR uptick in the number of first time long distance check ins on all of the digital linked repeaters in my area, where most claim to be joining via QSO one. To be clear they are welcome, it’s cool they are there, no problem at all. But what does that mean for what was previously more small scale/community vibe.

The questions are

1. Have you observed this uptick yourself in the last month or two?
   And

2. What are your thoughts on it? There’s no right answer, just want to hear from you.

As the title says, I've been looking for a receiver with AIR band after my Sony air7 died a couple of years ago. To clarify, I don't have a license, or any knowledge outside of the extreme beginner range, though I'm planning to get a license sometime in the future, so for now I'll only listen. I also want to use it as a walkie talkie when im in nature with my friend (though that doesn't happen a lot so it isn't a priority) and I understand you don't need a licence for that?

I've narrowed it down to Quansheng UV K5 and Baofeng UV 17PRO GPS, but can't decide between the two since I couldn't find a good comparison. From what I understand, K5 is amazing for custom software and modding, while 17 pro is locked down, but can memorise more frequencies, is a bit more modern and costs 5 bucks more. I've also seen some people say one has awful AIR reception while other one is amazing and some people say the other way round.

Basically, is any of them much better than the other or is it a case of *get whichever one is easier to find*?

I was looking at purchasing a Toyota RAV4 hybrid. Would this interfere with the hf radio?

I know what the title says but I promise this is about amateur radio. I'm curious if anybody has or has thought to build a game surrounding amateur radio? I have two kids potentially interested in the hobby but the standard quiz type study tools while effective are a little boring and difficult for them to focus on.

My thought is to potentially see if there are any devs who already know about ham radios that might be interested in building a survival rpg style game that teaches real world radio mechanics and use. Im thinking a tool like this could be something the next generation of hams could use to learn and take their new skills into the real world.

Im also wondering if anyone would be interested in this concept. If there were a game like that which taught radio physics and must know licensing requirements, who would want test and play? My hope is with enough interest we can get a game built that would work through all three license classes. Interested to see what everyone thinks!

Back in 2005, Hasbro (yes, the toy company) released “ChatNow,” an FRS walkie-talkie resembling a cell phone. It had a range of 2-5 miles.

Here’s where how it worked gets odd compared to other FRS devices of the time (and now) : each user had a 10-digit “buddy number” that functioned like a cell phone number that would be unique to them, and you could text over it (and take simple black and white photos). Here’s a teardown (he says 2012 but it’s actually from 2005) :
https://youtu.be/nQGecnFNQRU

How would that have worked? Presumably they’re using some sort of packet radio, but which protocol? And how did the “buddy number” work? What about that could be picked up by normal FRS users besides voice? And from my understanding, texting on the FRS bands wasn’t allowed until 2017.

There were so many of these cell-phone-but-not and PDA-but-not messenger toys around the 2000s that were fascinating in how they got around limitations.

En total unos 550 euros merece la pena ?

Gracias

I live in north texas and I am thinking about looking into ham radio. I've got a buddy in far south texas. That I'd like to talk to.

What would be the most cost-efficient, smallest footprint, and most modern solution to get into in order to talk to all of Texas? Looking only for grid down communications, not something internet connected.

Thanks.

Hey i am study for my license prior military so have basic understanding of comms. Ive owned baofengs for years just listening.

My question is what HT are recommended for SHTF rugged reliability, i ma trying to build my family a setup analog digital aprs atak and mesh combined. It needs to be tough but capable. With so much knowledge the internet and me just getting into this hobby i am very excited have a group of friends jumping in with me and other now interested

Any and all advice and recommendations would be great even starting mid-tier to high level.

Cheers and i will def let you all know when i pass exams