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Re: TX500: A Five-day Rollercoaster


 

Re individual incident...maybe not.

I managed to blow the audio amplifier chip in my TX-500 a few weeks ago just before the North American QSO Party SSB Contest operating from a portable location (Atlantic Beach, NC).? Lab599 Service USA quickly analyzed and repaired the TX-500.

Background: I had my TX-500 mounted to the side of an Elecraft KXPA100 with an external speaker and Heil HC4 mic element attached through the stock mic/speaker/PTT adapter. I also had a homemade adapter cable connected to the REM/DATA port providing PTT out to the KXPA100.? This connector also had wiring to PTT in, in which I had connected to a footswitch.? Although not being used, I had wires for the Audio In and Out.? All of the wires to the REM/DATA port were about 3 ft long and unshielded.? The 8 ft long footswitch cable was connected to the 3 ft wires via two 2 ft long alligator-clip leads.? The external speaker (MFJ-281) had a 4 ft shielded cable.? All of these wires were laying around loosely on the operating table.? The antenna was a PAR EF-QUAD in horizontal orientation about 30 ft from the operating position and was connected through 75 ft of RG8X.? Everything was working well, I made several POTA contacts on 40M that Saturday morning running around 50 watts from the KXPA100 (TX-500 Power at 50%).?

BTW, For those of us phone guys who don't carry a CW key everywhere we go, we use the "TUNE" feature, or some combination of buttons, of most other radios to generate a CW tone to adjust actual power out and check SWR.? There is no "TUNE" feature discussed in the manual.? After a reading of the manual I found the Menu Feature #24 Type Tone which discussed exactly what I needed.? But there was no reference to where to go in the manual for instructions on how to initiate the "TONE".? After doing a word search of the pdf file, I found the instructions in the Receive Settings section (last item) of the manual; not exactly where I was expecting transmitting details.

Event:? I increased the TX-500 Power to 75% and proceeded to check power output of the KXPA100.? On 40M I had around 90W, on 20M it was 100W and on 15M it went to 100W and a loud POP.? Not having enough time before the contest start to troubleshoot the issue, I packed up the TX-500/KXPA100 and all the wires.? I proceeded to operate the contest with my Elecraft K3/100.

Post Event:? After arriving back home I reconnected everything on the kitchen table.? I determined that the TX-500 receiver and transmitter were still working OK, and the audio out from the REM/DATA port was OK.? The only problem was no speaker audio from the MIC/SP port.? I packed the TX-500 and sent it to Lab599 Service USA.

Thoughts:? I know this is a new radio design and there may be unknown issues that develope over the early usage of the units.? So, now with possibly two audio amplifier failures, is this an issue or just two isolated instances?? I don't know.? Was my setup with all of the unshielded and long wires the path for RF from the nearby antenna the real problem?? If so, why didn't the event also eliminate the audio out from the REM/DATA port?? Was mounting it so close to the KXPA100 the problem?? I bought the TX-500 because of its unique packaging and features and plan to keep it.? I still have other radios to use if the TX-500 is not suitable for high RF environments.? It is still a great little rig for portable outdoor usage.? Since I left early for the beach, I was unable to use the TX-500 in this past weekend's Winter Field Day event.? My next opportunity to use the TX-500 will be at the end of the month during the CQWW 160 SSB Contest from the beach house.? When the weather gets warmer, I really will use the TX-500 alone in some outdoor setups.

Sorry for all of the details above, but wanted to provide information that might be useful to others with a TX-500.

I welcome any further thoughts or questions from others.? My next TX-500 project is an attachable battery pack.

73,
Henry - K4TMC


On Tue, Feb 2, 2021 at 8:07 PM Weishan Liao <weishan.liao@...> wrote:
Some of you might have been seeing my posts on the Facebook group, but I think I'd shared my though on the transceiver here as well.

As the leading SOTA activator in Taiwan, I think it is definitely one of activator's dream radios, sturdy body, weather-proof, nice screen for both indoor or outdoor, and most importantly, it has perfect user interface, functions that needed for filed operation is very easily accessible.

However, my experience with my particular unit is kind of a rollercoaster.

I ordered directly from Lab599 and I asked them to ship it without the box in order to avoid some tax and customs issues. I ordered in September, Lab599 shipped it in late October and after almost 100 days, it finally arrived Taiwan. The delay was of course due to the pandemic.?

Although radio was packed in multiple layers of bubble wraps, upon arrival I discovered that the BNC connector was dented, and after powering up I found the "B" icon is always there and the radio couldn't remember any of the user settings. I open the radio and found a broken socket for the CR2032 battery. The Lab599 team is very responsive and helpful, they offered to send me a replacement unit but I may have to wait for another 90+ days for it to arrive. They also sent me video instruction on how to replace the BNC jack and the battery socket and promised that doing that on my own would not void my warranty, I opted the latter and installed new jack and socket, problem solved.

Just when I though my TX500 was about to sail to a new life, I encountered another?swirl. After several QSOs on phone and FT8 at home, I took it for its first field operation yesterday, I used a load GP with adjustable coil, at first everything went well on 40-meter band, and then I switched to 20, tune my antenna to perfect 1.0 SWR and began to TX on FT8. All of sudden, my own FT8 TX came out from the speaker with the monitor off, I stopped and only to find out the speaker is not working anymore, there is just no sound coming out, I tried reset, re-flash the firmware, taking the internal battery out and put it back on, as well as using the headset adapter to rule out the problem on the speaker-mic, but the radio just went dumb, even the internal buzzer for the key beeping became silent. The RF capability? (TX and RX) seem to be intact judging form the panadapter and the FT8 QSO that followed.

I have contacted the Lab599 on this matter and I think I may have to get and wait for the replacement afterall. But again, nice radio! I hope this is just an??individual incident.

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