Date   
Re: FT8 DSB VOX

John Kirby
 

Adam,

My RockMite mod for FT8 DSB (NOVOX (yet hi hi))

John
N3AAZ

Re: FT8 DSB VOX

John Kirby
 
Edited

ps ...

Q2 has no FT8 function (yet)

John N3AAZ

Re: FT8 DSB VOX

Adam Rong
 

Good job on the modification. It saves $ and time.

I sent 4 kits to domestic hams based on the first version PCB, and 3 of them completed the building, although they did have a few questions and mistakes.  1 more person will start building tomorrow. 2 of them logged QSO’s so far and 2 of them told me they got about 2 watts when it is powered by 13.8V. 1 of them told me the design is mature, so I will start PCB massive production tomorrow.

Thanks,
Adam

在 2019年4月21日,下午11:53,John Kirby <n3aaz_qrp_1@...> 写道:

Adam,

My RockMite mod for FT8 DSB (NOVOX (yet hi hi))

John
N3AAZ
<20190421_113518.jpg>

Re: DSB transceiver for Digital mode

Adam Rong
 

Technically it is possible. Just change the crystal and I might be able to customize it. However, we will need to consider the unwanted LSB signal will go into FT8 spectrum and it might cause interference although the power is still QRPp level.

If we want to experiment, just pull high the crystal a bit to see how high it can go, maybe 7075 or 7076 but not easy to get 7078 for a HC49S holder crystal.

Thanks,
Adam

在 2019年4月21日,下午10:39,Jim <KH2SR@...> 写道:

Would it be possible to make this rig operate on the JS8CALL frequency of 7.078 instead? 

Re: DSB transceiver for Digital mode

Jim
 

What about having both crystals and then adding a switch to go between the FT8 and JS8 frequencies?

Re: FT8 DSB VOX

John Kirby
 

Adam,

Sounds good !
Will you release the schematic even if preliminary ?

72 73
John
N3AAZ

Re: DSB transceiver for Digital mode

Adam Rong
 

Jim,

I would leave it for customers’ modification. We have added a crystal in the front end as the filter. We will have to switch both.

Thanks,
Adam

在 2019年4月22日,上午12:48,Jim <KH2SR@...> 写道:

What about having both crystals and then adding a switch to go between the FT8 and JS8 frequencies?

Re: FT8 DSB VOX

Adam Rong
 

John,

No. I will keep the schematic paper based only for customers for a period of time.

Thanks,
Adam

在 2019年4月22日,上午1:20,John Kirby <n3aaz_qrp_1@...> 写道:

Adam,

Sounds good !
Will you release the schematic even if preliminary ?

72 73
John
N3AAZ

Re: FT8 DSB VOX

John Kirby
 

 
Adam,

I understand and thanks for the reply

72 73
John
N3AAZ

Re: DSB transceiver for Digital mode

Adam Rong
 

Folks,

I have placed order for PCB two days ago. The first batch is 350 pcs.

I have finalized the parts value and will place order for parts tomorrow. The RF output is 1-watt at 12V for 14.074MHz, and a bit bigger for 7.074MHz. The spurious suppression is better than -50dBc.

I hope to start kitting for the first 5 pcs on May 4. If it goes smoothly, I might take order to ship these kits early, so you can send a few test reports ahead of time than the usual customers. Stay tuned and I hope you will like it.

Thanks,
Adam

Re: DSB transceiver for Digital mode

Furtuna Mircea
 

Hello.
Cut the crystal around 1mm around the crystal, scratch the crystal very carefully, just a little, and measure it frequently.
It will be a slight increase of 30 maximum 100kz.
Verified method, step by step.
Mircea-YO9IOF

On Wednesday, April 24, 2019, 7:46:13 PM GMT+3, Adam Rong <rongxh@...> wrote:


Folks,

I have placed order for PCB two days ago. The first batch is 350 pcs.

I have finalized the parts value and will place order for parts tomorrow. The RF output is 1-watt at 12V for 14.074MHz, and a bit bigger for 7.074MHz. The spurious suppression is better than -50dBc.

I hope to start kitting for the first 5 pcs on May 4. If it goes smoothly, I might take order to ship these kits early, so you can send a few test reports ahead of time than the usual customers. Stay tuned and I hope you will like it.

Thanks,
Adam

Re: DSB transceiver for Digital mode

Adam Rong
 

80-meter 3.573MHz will be added. Crystals are being customized. Think of a 80-m radio of 1-watt to make a few QSO's? Great fun!

Thanks,
Adam

Re: DSB transceiver for Digital mode

Ron Stone
 

Adam,

Glad to see that you're going forward with 20 meter version sooner rather than later.  Are you getting customized crystals for 14.074 Mhz or is it anothet frequency crystal that has to be pulled a bit?  If so what frequency is it for 20 mtrs?  Thanks.

Ron (ka3j)

Re: DSB transceiver for Digital mode

Adam Rong
 

Ron,

I use 14.070MHz HC-49U crystals and pull them high about 4kHz. The crystals were customized before and I have enough stock. They work perfectly for 14.074MHz.

Thanks,
Adam

Re: DSB transceiver for Digital mode

Adam Rong
 

Folks,

This is a bit history for D4D: A simple QRP transceiver kit for FT8.

D4D stands for DSB transceiver for Digital modes. It is a Double Sided Band transceiver kit designed for digital modes, especially for FT8. If you have chance to try FT8, you will be amazed by the strong decoding capability due to the communication protocol, digital signal processing and software. I still remember clearly a YouTube video by W6LG who communicated with a bulb. I started to think how much the transceiver could be simplified if you have a moderate antenna like a full sized dipole or EFHW instead of a bulb. A DSB transceiver is much simpler than a SSB transceiver, however it was never used for FT8 as far as I know. I did some experiments on my Choc perf board, a specially designed perf board for RF circuit experiments. I started with a direct conversion receiver for FT8 and it worked okay. Then I built a DSB transmitter and the transmitted signal can be decoded. By referring to the DSB designs of AA7EE, VK3YE and ZL2BMI, I combined them using only one NE602 and a PTT switch and it gave me success to make a few FT8 QSO’s. Personally I really enjoyed it because a manual PTT switch will save power consumption and circuit complexity, but you will need to well sync with computer, although it was not really a problem for me. Per request from a few hams, I found a VOX control circuit and modify the hold time to be compatible with FT8, and I put them together and made a few improvements on the signal purity and frequency stability, and it finally became our D4D. Do we have to worry about the unwanted Lower Side Band? Maybe, but for a transmitter of 1-watt, it is not really a big problem. Is it just a toy for a transmitter of 1-watt and only half of the power will be effective? Not really, as I can easily make a few QSO’s as far as 1500 miles range for 40-meter band.

Thanks,
Adam


在 2019年4月26日,上午9:05,Adam Rong via Groups.Io <rongxh@...> 写道:

Ron,

I use 14.070MHz HC-49U crystals and pull them high about 4kHz. The crystals were customized before and I have enough stock. They work perfectly for 14.074MHz.

Thanks,
Adam

Re: DSB transceiver for Digital mode

Adam Rong
 

Folks,

I have put together a final version and it worked perfectly. Now I accept order for beta testing.

 I will ship 3 kits of 7074 by May 6. If you join beta testing, you will need to keep secret before Hamvention debut. You will have time and equipment to build and test the kit and publish a test report. If you have a popular YouTube account or web site, please let me know so you will have priority. Please contact me offline.

The MP version will be shipped on May 20.

Thanks,
Adam

Re: FT8 HT

Adam Rong
 

In case you are following this thread, please see this:
https://groups.io/g/crkits/topic/31005901#2560

Now the idea comes true.

Thanks,
Adam

Re: DSB transceiver for Digital mode

Adam Rong
 

Folks,

Well, it was leaked by qrper.com. Check it out for now, although some data might be modified later.

Thanks,
Adam

在 2019年5月2日,上午5:19,Adam Rong via Groups.Io <rongxh@...> 写道:

Folks,

I have put together a final version and it worked perfectly. Now I accept order for beta testing.

 I will ship 3 kits of 7074 by May 6. If you join beta testing, you will need to keep secret before Hamvention debut. You will have time and equipment to build and test the kit and publish a test report. If you have a popular YouTube account or web site, please let me know so you will have priority. Please contact me offline.

The MP version will be shipped on May 20.

Thanks,
Adam

Stay tuned for more analog kits

Adam Rong
 

Folks,

I just realized that FT8 is so popular that someone loves it and someone hates it. However I hope in here both digital and analog kits can coexist. D4D actually is an all analog transceiver without MCU, DSP or SDR. It can used for FT8 and FT4 but it can also been used for voice transmission as long as the input is big enough to drive the VOX.

Currently we are offering HT-1A CW dual bander which is a cool radio kit. And we also offer R3500D ARDF 80m receiver. Both are analog radios. I discussed with team and we are going to release the successor of KN-Q7A. We don’t have timetable yet but we think it is a good direction to go. I also like to introduce my minimalist NE602 receiver as a kit. It was kitted based on my Choc perf board for Japan and I want to make a PCB and find a case, so it could be used for a club project. Stay tuned although we are discussing a little bit more about FT8 and D4D these days.

Thanks,
Adam

New file uploaded to crkits@groups.io

crkits@groups.io Notification <crkits+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the crkits@groups.io group.

File: d4dpartlist20190504.xls

Uploaded By: Adam Rong

Description:
D4D part list for 40m and 20m

You can access this file at the URL:
https://groups.io/g/crkits/files/D4D%20Kit%20Documentations/d4dpartlist20190504.xls

Cheers,
The Groups.io Team