Re: D4D 20m For sale
Adam Rong
|
|
Re: D4D 20m For sale
N8DAH <Dherron@...>
Some pics
|
|
Re: D4D 20m For sale
N8DAH <Dherron@...>
Still for sale 40$ shipped.
|
|
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: D4D Kit Assembly Manual Rev.B.pdf Uploaded By: Adam Rong Description: You can access this file at the URL: Cheers,
|
|
Re: Field Day Equipment of D4D and Raspberry Pi
Adam Rong
Folks,
I just posted to YouTube with some editing: https://youtu.be/la6BSmRS0k0 Thanks, Adam
|
|
Field Day Equipment of D4D and Raspberry Pi
Adam Rong
Folks,
Hopefully you can view this video. Should you have any questions, please reply to this thread. Enjoy. https://mp.weixin.qq.com/s/u7VGaNoBkQkuLb68LNZUFg I hope I can put on YouTube in a few days with some editing. Thanks, Adam
|
|
Re: Tecsun 2P3 AM radio kit
The kit may be purchased through Amazon. Just FYI.
On Fri, Jun 14, 2019, 5:43 PM Adam Rong <rongxh@...> wrote: John,
|
|
Re: Tecsun 2P3 AM radio kit
Adam Rong
John,
Indeed. Tecsun is the number 1 company in China to produce radio receivers. The kit quality is superb. Thanks, Adam
|
|
Re: Tecsun 2P3 AM radio kit
Adam Rong
Matthew,
I offered the kit a few years ago but discontinued later. You can purchase from other channels now. Thanks, Adam
|
|
Re: Tecsun 2P3 AM radio kit
matthew cook
I see the manual on the site but not the kit? Will it be available soon? Also some pictures would be cool. Tks for the info...
|
|
D4D 20m For sale
N8DAH <Dherron@...>
Built, tested, working with one of the IMD mods. Built for 20m solid 1w+ out (was getting 1.2w but turned it down for 1w) asking 45$ shipped conus (will ship over seas but must help with shipping) 73 David N8DAH contact off site gud on the zed.
|
|
Re: Tecsun 2P3 AM radio kit
Thank you for bringing this to our attention Adam!
It looks like a fun project. 73, John AA7US
|
|
Re: D4D: Modification for better IMD
Adam Rong
Folks,
Please read the deep modifications from BH4DCL. He modified LPF, PA bias, VOX and the power on transient transmission. Again, please use Google translation to read this page in Github: https://github.com/cnsit/radio/blob/D4D/articles/D4D.md Also, if you find it is easy to get the VOX mis-triggered in TX after you modified the #1 in the manual to improve IMD, you can add a 103 cap at the Audio In connector. Thanks, Adam
|
|
Re: D4D: Modification for better IMD
Adam Rong
Tom,
We were discussing the way Elecraft K2 adopted in their SSB option board that you can download from here. See page 24 for balanced modulator portion. The 1M pot is connected to pin 1, 2, 3 of the NE602. https://ftp.elecraft.com/K2/Manuals%20Downloads/ksb2%20manual%20rev%20G.pdf However, we found that this way is not effective most of the time. The way to add a diode will reduce the power supply voltage and it is kind of design of experiments from BH4DCL. Thanks, Adam
|
|
Tecsun 2P3 AM radio kit
Adam Rong
Folks,
While I was reading a post in SWLing, I think that you might be interested to read my translation of the manual, although the version might be old. The kit is still available from many channels if you are interested to build one. In the mid 1960's, with the population of transistors, radio amateurs of China were passionate to build their own radio receivers. It was a dream to have a good looking case for their homebrew radio receiver, so 2P3 case appeared. 2P3 was compact and beautiful. Once it hit the street, it was welcomed. Many people saved money for buying one, and built various radios from single transistor to six transistor superheterodyne with it, and the dream of building a transistor radio with a case came true. Half a century has passed, but those senior radio amateurs still can remember 2P3. Once talking about transistor radios, 2P3 is always a hot topic. People smile if they were lucky to have built one, and regret if they failed. However, 2P3 is seldom found these days, and it becomes a product for collection. So, it becomes a new dream to own 2P3 again! We reproduced 2P3 case, and designed and produced a superheterodyne radio receiver kit based on the current component characteristics. Hopefully it can fulfill the senior radio amateurs' dream, inspire the interest of the new generation and help improve their hands-on capabilities. CRKITS is now proudly introducing the kit to the worldwide. The kit manual translation is dedicated for our customers, to match our standard of service. Thanks, Adam
|
|
Re: D4D: Modification for better IMD
tom
I'm a little late to this group and am not aware where the 1 meg pot was to be connected, or why. Also what does the diode actually do to improve reception or transmission?
Thanks very much Tom.
|
|
Re: D4D: Modification for better IMD
Adam Rong
Correct. 1M Ohm pot is no need.
toggle quoted messageShow quoted text
Thanks, Adam
|
|
Re: D4D: Modification for better IMD
Mark Sykes
Adam,
The 1N9148 diode in the cut trace for modification 2 carrier leakage: That is instead of the 1M Ohm pot? Thanks, Mark KD8RG
|
|
Re: D4D: Modification for better IMD
Adam Rong
Folks,
toggle quoted messageShow quoted text
For the modification 2 in the full manual, you can try a better solution. Cut a PCB trace and add a 1N4148 diode as the following picture. It will improve the carrier leakage by about 10dB. So far I haven’t seen any significant side effect. This modification is suggested by BH4DCL. Thanks, Adam
|
|
Not D4D: How simple a FT8 receiver can be?
Adam Rong
Folks,
This is my experiment. I just used a NE602 and a few passive components. Use Google translation to read this: https://mp.weixin.qq.com/s/-Es5XWPcKTXxAZ8qdjIk4g Thanks, Adam
|
|