*. 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.
YD1OSC (ex YD6DEK)
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.
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 HF transceiver spec:
- 3.2 Inch TFT LCD
- Si5351 synthesizer
- VFO-BFO out
- SSB/CW/AM/FM mode
- 8 Band Control
- BITX based heterodyne transceiver
- 10MHz IF
- 300-3000 Hz audio band pass filter
- 5 band BPF off 8 band control
- 5 band LPF off 8 band control
- 30m + 20m
- 17m + 15m + 10m
- 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
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.
- BritX exciter, based on BITX exciter with on board 2 to 30 Mhz fixed inductor BPF using FST3253 band switch
- Small form factor (common component are smd)
- RTC02B controller (2.2 TFT display) with special firmware
- ABS enclosure with acrylic panel
This exciter will be power up with 10watt linear amplifier. using RD16HHF1, and RD00HHF1 as driver and 4 Band LPF
In the future there will be an additional daughter board to improve bitx performance like:
- 3-5 Watt audio amplifer with AGC
- DSP audio processing for speaker
- DSP audio processing for microphone and also audio compressor
This exciter availabe now in Indonesia, please visit to buy it..
BRHF10 = BRitX + RTC02B