HBR10HF intermittent blank or gray/white LCD on start problem solving

Hambuilder HBR10HF using RTC03 as controller with 3.2 (320×480) TFT LCD. This item worked very nice, good color,  viewing angle, speed (using 16 bit parallel data). But the main problem is the availability is a night mare. I using this TFT since early 2016 when I started to build the RTC03.  Until now, this TFT already have 3 difference controller in market, with 3 difference firmware and specification and the worst is, seller from China that I bought this TFT did not know and did not help what kind controller or even give me any datasheet. I must find out by my self how to make this LCD works.

its look same but they have difference

when you look at their back side its HX8357C, V2.0 and blank, its all false
The HX8357C using ILI9481, the V2.0 using HX8357D and the blank one using HX8357C.
They need difference firmware and have difference command, and what I want to tell here is they have difference habit and speed. The blank one do not need hardware reset, but the other one intermittent required. This habit make your RTC03 sometime show the white or gray or even blank display on start.

How to solved this problem? actually is very easy (this bug already solved on our production line), please check the image below. We just need to added R-C reset delay. please see the picture below

and implemended like this on your RTC03, I choose R 10K and C 100nF.

Then if you get your RTC03 with intermittent gray or white screen on start you can applied this solution.

Best Regards
Hambuilder team


HBR4HF (RTC01C + BritX tranceiver) tunning

Similar condition with HBR10HF some buyer report carrier leakage on HBR4HF, same proble with his brother HBR10HF, BFO level is too big injected to modulator. Here’s the solution :

*. Replace BFO coupling from RTC01C with 100pf value
*. Tunning the preamp trimpot
*. Tunning the carrier balance
*. Adjust gate bias voltage (Vgate) into 3V






How ever please take note, power of the transceiver considering many thing not just increasing the final stage value. We must consider also the cabling, switch relay, PCB track and etc. HBR4HF and HBR10HF not designed to produce big power.

Hambuilder team

Tweaking BritX based Hambuilder exciter (carrier leakage #1)

For older version of britx based (BITX) Hambuilder transceiver some buyer reported carrier leakage during transmit, its also affect the microphone gain setting. Please find the attached document for missing part and revision.

Hambuilder team

HBR10HF and HBR4HF front panel face lift

HBR10HF facelift :

*. Additional phone jack
*. Additional key jack
*. Additional pc audio in and pc audio out
*. 5cm Aluminum rotary knob for freq dial

HBR4HF facelift :

*. 2.0 inch TFT display replacing 16×2 char LCD
*, Additional phone jack
*. Additional key jack (back side)
*. 5cm Aluminum rotary knob for freq dial

Hambuilder team

Hambuilder SSDR100 prototype

This is the next Hambuilder transceiver (SSDR-100)
*. 3.2 inch TFT display
*. STM32F407 as display control and waterfall processing
*. ATMega8 (21st order FIR LPF processing)
*. Weaver SSB modulation and demodulation method using 2 x ADC MCP8201 and 2x DAC TDA1543
*. Embed CW decoder/Encoder using ATMega8
*. Bluetooth Access for setting, remote access and firmware upgrading
*. Android remote access Apps
*. 18 button access for band and control
*. 1 rotary main dial
*. 3 rotary for RIT/XIT, Bandwith Control and WPM
*. PC audio interface for digital mode
*. 80-100 Watt power out

Hambuilder Team


HBRADD1 for HBR4HF, CW Encoder-Decoder and Digital Mode set-line

HBR4HF memang menggunakan desain klasik dengan fitur yang umum saja. Beberapa rekan mempertanyakan mengenai absen nya mode CW dalam desain HBR4HF. Hal tersebut sebetulnya sudah masuk kedalam road map pengembangan yang sebetulnya sudah sangat lama di desain. HBR4HF memang dibuat sederhana sebagai pintu masuk kedunia HF dengan pertimbangan harga dan memang faktanya untuk amatir lokal rasanya masih sangat terbatas penggunaan mode selain SSB.

HBRADD1 adalah road map setline dari HBR4HF, mengapa dibuat terpisah, kembali ke alasan harga serta tidak semua amatir menggunakan CW, HBRADD1 juga memungkinkan di kembangkan dengan fitur GPS (APRS) bila nantinya mau dikembangkan untuk radio matirim yang murah. Pada BRHADD1 ini juga telah dilengkapi interface ke sound card PC bila rekan-rekan ingin bereksperimen menggunakan digital mode via PC sound card. Pada HBRADD1 ini juga di tambahkan 5 watt audio amplifer dengan loudspeaker yang besar melengkapi loudspeaker yang ada pada HBR4HF.

Spesifikasi :
*. ATMega8 as main controller for CW decoder and display
*. NE567 as tone decoder
*. ATTiny13 Iambic keyer and PTT control with buzzer tone
*. 16×2 character LCD for TX and RX CW encoder/decoder
*. 3-5 watt audio amplifer
*. 1 x 3.5 mm audio jack for Iambic keying input
*. 1 x 3.5 mm audio jack for sound card interface input
*. 1 x 3.5 mm audio jack for sound card interface output
*. 2 x 600 ohm audio transformer sound card in and out audio
*. 5 watt speaker
*. Dimension 200(w) x 60 (h) x 100 (deep) mm



Hambuilder Team

HBR4HF – Hambuilder 4 Band HF Transceiver

HBR4HF specification

  • Heterodyne 10MHz Xtal filter exciter based on Hambuilder BritX exciter
  • 300-25000Hz audio band pass active filter using NE5532
  • 4 Band coverage (80m, 40m, 30m, 20m) with 3 selector LPF BPF
  • 20-35 watt RF power output,
  • 2x IRF 530 Final RF amplifier
  • SSB modulation
  • 16×2 char LCD
  • Si5351 VFO and BFO synthezyzer based on RTC01C controller