Video of how to take the Wouxun apart, complete down to the board level. Overview of repair areas.
BFDX TD-503 DMR RADIO
I've been using the BFDX TD-503 for several months on the local DMR repeater and NCPRN. The main reason I really like it and its found its place above my Mototrbo and Hytera is it the GUI by default shows the Frequency and Channel Name. Controls are standard and easy to use. The case is high quality and it has some heft to it.
It has been left out in the rain, taken on swift-water calls (submerged in the river), dropped, banged, and otherwise abused with no issues whatsoever.
Programming is easy and the cable is inexpensive. The audio quality is better or on par with both my Hytera and Mototrbo's in both analog and digital mode. This radio works great on analog repeaters as well. I've been using this pretty much exclusively for any outdoor adventures (UTV'n, Rafting, Swift-water Rescue, Climbing) without fail, mainly because of its price point and performance. At $250 brand new its much less expensive than a used Mototurbo or Hytera.
I had some issues with the audio on this so bear with it. Also standard definition only.
Just a quick video of what's next in Ham radio and some projects I've been working on, as well as others, to get there. Some highlights:
- MultiCodec - Codec2, AMBE...
- Remote Standardized Head Unit / Retrofit
- Less PC .. More Embedded
- More modular
- Easier to use and the possibility of installing station away from Radio.
- DSP development in the hands of more people.
- Older Designs get updates.
- Powerful Tools getting more accessible
- KiCad (New stable, RF Traces (Curved), Diff Pair Routing (USB, etc))
- Inexpensive STM32 and other DSP platforms
- Filter Creation and Simulation
An open source codec for compression is up and going (CODEC2).
AMBE is much easier to implement and get ahold of.
Remote heads are beginning to pop up commercially in the FlexRadio line.
More embedded projects/products including SM1000, FlexRadio head unit, and many many DStar node adaptors.
DMR radios have hit the market to warm up the digital voice market, many which are under $300 new.
I've been looking at migrating some of the work I've done on my ComboStar build to VHF/UHF including GSMK and Codec2. With 3D printed case, lithium battery, STM32F405, DRA818V/U, and a nice OLED screen I think its possible to build a DIY 1 Watt radio that support analog, FSK (APRS), and Codec2 GSMK. I already have several working STM32 projects with successfully generating various modulations including GMSK, POCSAG and AFSK. My first step is to play with the DRV818V module and see how difficult it is to implement. From the datasheet I've included a low pass filter in this prototype which I should be able to prototype with my existing STM project board.
I've taken on yet another TS-430 and ran into an issue with whats coming off the PLL board. I traded a TS-430 I had purchased as non-working which I repaired/tuned for a unit in very nice shape cosmetically but not working. Another HAM back on the air, but now I have another TS-430 to figure out. I suspect this may be an issue with VCO signals coming to the PLL but after spending several hours getting to this point, I've put the project down for a bit to work on my workshop. Hopefully someone on a list somewhere has seen this before and I'll hear back from someone by the next time I pick this project up.
I have a HP 8935 E6380A service monitor that had some pretty severe screen burn. After looking around for a replacement I wanted to see how hard it would be to adapt a current LCD to the 8935. Suprisingly it was fairly easy. I had a 10.5 inch display and after probing around a bit to see what signals/power were on the A1A1 connector (400 i think) I started playing with a FPGA dev board to convert signals to something I could see on the screen. It works but doesn't fill the entire screen and its not the right size hardware. Now that I have a PLAN B and I've found a 6.5"ish lcd I can readily buy cheap, I'll troll along with the burnt display till it fails or I can't stand it anymore. I'm hoping there is a lot of interest in this to other 8935 owners and its something I can justify doing in the near future.
Some things I played with while I had the 8935 apart and the 10.5" connected:
- Inversion to have some way of preventing screen burn.
- Adding some color (Changed boarder color, changed color of spectrum analyzer portions of the screen) This isn't something that can be done everywhere. If its simply which pixels get what color it's trivial.
- Added text to the parts of the screen not used going from 512x256 to 640x480. Could add ADC to show voltages etc as extra info.
-Centered screen and added border.
I recently discovered my B & K E200D would no longer modulate while working on a Kenwood TS-440AT. After getting inside the E200D nothing appeared to be unusual and I remember a site I had used before when searching for the switchcraft connector I needed to make a cable for this unit. http://www.freeinfostuff.com/E200D/E-200D.htm . After going thru the calibration procedure, everything was in calibration with the exception of the modulation level which once I adjusted the level the modulation meter was back in action. Easy quick fix and now I know that the unit is calibrated.
I recently purchased this Tempo 2020 HF radio to rebuild. I plan to start this project after the TS-430S is finished.
Yahoo Tempo Group (Very Useful) http://groups.yahoo.com/group/TEMPO_2020/
KX4OM Tempo 2020 Repair pages http://www.kx4om.com/TechSolutions/Tempo2020_repairs/2020.html
I've had several email's about some of my test gear in recent weeks and one item of interest from many was the cable used on my B&K E-200D Signal Generator. I used a premade 50 ohm BNC cable and attached a 2501F connector. So if you need these connectors they can be found numerous places. Search for 2501F, vintage mic connector etc to locate the connector. I prefer when possible to keep my gear original in case I sell the unit for an upgrade and the cost of the connectors is very small. I was able to purchase two for less than $12 including shipping. On is a BNC adapter and I used the other for a 50ohm gator clip style cable. Switchcraft is the manufacture of the connectors I used.
The datasheet is below.