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

Tweaking BritX based Hambuilder exciter internal speaker and headphone jack

First version of HBR4HF or HBR10HF are used hybrid microphone with loudspeaker. Basic idea using this is to reduce complexity and cost. also considering it as portable radio. How ever there’s a requirement to operate with external audio amplifier or external speaker for better audio receiving. The newest HBR4HF already have internal loudspeaker, and the newest HBR10HF already have audio jack also.


Hambuilder team

Lebih jauh tentang HBR4HF

HBR4HF didesain sedemikian rupa untuk memenuhi kebutuhan rekan-rekan di Indonesia yang lebih dominan beroperasi di low band HF (80-40m). Mungkin perlu juga dipertimbangkan regulasi yang membatasi rekan-rekan amatir dengan tingkat siaga bisa ikut mencicipi band-band lain di spektrum HF.



Berkebalikan dengan desain-desain sebelumnya dimana blok demi blok didesain pada PCB terpisah, HBR4HF menggunakan 1 keping PCB untuk fungsi-fungsi exciter, band pass filter, low pass filter serta RF power amplifier. Hanya controller yang terpisah mengingat PCB controller akan di pasang pada panel depan. Desain pada satu papan PCB menyebabkan tidak di perlukannya interkoneksi antar board. Pada gambar berikut terlihat item-item apa saja yang masih perlu disambungkan agar dapat berfungsi penuh sebagai satu transceiver.


Penampilan PCB HBR4HF setelah proses perakitan.

Terlihat ada 2 buah transistor IRF530 pada sisi PCB yang akan ditempelkan pada heatsink di belakang box. Bila diinginkan power out yang lebih besar, silahkan bereksperiment dengang mengganti MOSFET IRF530 dengan jenis yang lebih besar atau menaikkan tegangan kerja MOSFET final ke 24V, dengan catatan kerja MOSFET ini di pisahkan dengan tegangan kerja komponen lain pada PCB (pernah di coba dengan menggunakan 24V akan diperoleh power output 45Watt)




Hambuilder Team

BritX and HBRF01 listed on eBay

Dear All friend,

The exciter BritX and Combo BPF/LPF board listed on eBay, its your time to build your full system transceiver using hambuilder transceiver module

BritX exciter board on eBay


HBRF01 listed on eBay



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

RTC03 + BritX (All Band SSB) + Wide BPF/LPF + RF-PA20(4xIRF510), Its almost complete now

I got many request from friend to listed full set of transceiver module on ebay. Its already pushing me hard to realize it as soon as possible. Really hard to worked with my “pneumonia” problem since last year, I didn’t smoke but its happen to me because the air conditioner bacteria. I have a full day jobs as a SAP consultant. Yes, It mean lot to do but I tried to build it as soon as possible, and this post is the progress.

Nothing new design of this BritX, its just some variance of famous BITX, I just added and replace some component exist on local, plus an audio band pass filter to make better audio in receiving. Everything is generic design but, my big job is to make all module work together in all band, its not easy, at least for me. After some PCB design, prototype testing, testing and again testing. Its worked now.

The transmit test result with 13.8v supply with dummy load after lowpass filter:
1. 160m 16.3Watt
2. 80m  17.7Watt
3. 40m  25Watt
4. 30m  20Watt
5. 20m 24Watt
6. 17m  22Watt
7. 15m 19.3Watt
8 10m 8.3Watt

Yes power out is getting low on the 10m band but its common for IRF510 mosfet. Using RD16HHF or RD70HHF will be a better with flat RF output on all band. For my friend thats already bought my RTC03 on eBay, please be patient this complete set will be list there soon.


All Band BPF/LPF

All Band BPF/LPF

Dian Kurniawan