New HBR4HF released

New HBR4HF is a compact 4 Band HF transceiver.
This simple and low cost radio is also suitable for entry level HAM to start do communication on HF band.

*. Assembed unit, tested and ready to use.
*. New 2.2 Inch TFT display,
*. 4 amateur band (80m, 40m, 30m sharing filter with 20m)
*. TX covering 80m/40m/30m/20m,
*. RX covering 3.5-14.5 MHz,
*. Step 1Hz, 10Hz,100Hz,1KHz,100KHz,
*. Output 13.8V 45-50W,
*. CW SSB modulation with 700Hz tone,
*. Display VFO A/B, mode, Smeter, Band, RX/TX.
*. IF Freq 11.059.200.

Band Coverage (programmable) :
80m (3.500.000 – 4.000.000)
40m (6.000.000 – 7.250.000)
30m (10.100.000 – 11.500.000)
20m (14.000.000 – 14.349.999)

*. Exciter complete set
*. DC chord
*. Condenser Microphone

store link New Hambuilder HBR4HF



Hambuilder Team


HBR10HF new board design with ADE-1 as RF mixer

Specification :
*. BRITX Based
*. Front End RF gain using 2SC2570
*. Front End RF attenuator
*. TX RF attenuator
*. ADE-1 main mixer (detachable)
*. Detachable ladder filter
*. CW generator/Key PTT delay on board
*. AGC on board
*. Band Pass Filter on board

By replacing main mixer with ADE-1 we can get very good carrier suppression, increase sensitivity, and we can get more TX power on almost band. We also added crystal ladder filter adapter, so it can be upgrade next.  You can replace the crystal with your mechanical filter (please take note the impedance matcing), or you can make variable BW filter by using varicap diode.

We decided to use separate RF amplifier board with LPF on it. We hope we can increase the power out, but still using the low cost MOSFET.

Dian Kurniawan

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

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






Hambuilder HF modular transceiver (RTC03+BRITX+BPF/LPF+HBRPA20)




Transceiver Block

Hambuilder HF transceiver spec:

  • RTC03
    • 3.2 Inch TFT LCD
    • Si5351 synthesizer
    • VFO-BFO out
    • SSB/CW/AM/FM mode
    • 8 Band Control


  • BRITX-01
    • BITX based heterodyne transceiver
    • 10MHz IF
    • 300-3000 Hz audio band pass filter
    • Smeter
    • Agc


  • HBRF-01
    • 5 band BPF off 8 band control
    • 5 band LPF off 8 band control
    • 160m
    • 80m
    • 40m
    • 30m + 20m
    •  17m + 15m + 10m
    • IMG_20170717_095323


  • HBRPA20
    • 1x IRF510 driver
    • 4x IRF510 final
    • 0.5-1 watt input
    • 13.8V operation
      Test result with LPF and 50 ohm dummy load

      • 160m…….. 17 Watt
      • 80m ……… 15 Watt
      • 40m………. 19 Watt
      • 30m………. 16 Watt
      • 20m………. 22 Watt
      • 17m……….. 17 Watt
      • 15m……….. 18 Watt
      • 10m……….. 10 Watt


HBR TRX Connection 5

Hambuilder Team

RTC01C Enclosure prototype

Melanjutkan pengembangan RTC01C berikut adalah salah satu protoype enclosure RTC01C. Pada prototype in masih menggunakan plastik abs sebagai bahan dasar, namun pada produksinya direncanakan untuk menggunakan aluminun sebagi bahan dasarnya.

Ukuran di perkirakan 6 x 20 x 20cm, diharapkan cukup kompak tapi bisa menampung
*. sebuah board exciter seperti bitx,
*. PA (10-20watt),
*. 5 band set LPF + BPF
Rasanya masih cukup kecil dan ringan apabila hendak dibawa portable.

Diharapkan akan muncul setline nya berupa Power amplifer hingga 80 watt dan antenna tuner L-C plus pick up SWR nya juga dengan LCD 16×2.

Berikut bentuk nya yang minimalis, khusus mic amplifier, dan agc pre setting saja tidak disedikan lubang pada panel untuk mengatur hal tersebut.