D4D: Modification for better IMD
Folks,
Please refer to the photo to make modification to improve IMD. The RF output will be impacted but it is worthwhile to do so. Replace C5 by 103. Remove C6. Add a 1uF-10uF cap. Add a resistor of 22-27 ohm. Make connection as follows. Connect the positive pin of 1uF to the upper pad of C6. Connect the negative pin to the interconnection of 22-27 ohm and the original 330 ohm. Remember to adjust the audio output to just stably trigger the relay.
Thanks,
Adam
|
Re: D4D: Test 30m JS8CALL
Folks,
Just completed the first 10.130MHz D4D with success. I will build one more tomorrow. Thanks, Adam
On Sat, May 25, 2019 at 2:03 AM Jim < KH2SR@...> wrote: Hi Adam. I am a avid JS8CALL user and I would be happy to test out 30m. I could then add it to the review I am doing for you.?
James Hannibal - KH2SR?
|
Re: D4D: Test 30m JS8CALL
Hi Adam. I am a avid JS8CALL user and I would be happy to test out 30m. I could then add it to the review I am doing for you.?
James Hannibal - KH2SR?
|
Re: D4D: Test 30m JS8CALL
Planning on it in 14 to 30 days.? :-)
On Fri, May 24, 2019 at 12:24 PM Adam Rong < rongxh@...> wrote: Folks,
Anyone is interested in testing 10.130 version for JS8CALL? Beta testing is required as JS8CALL activity is low here.
Thanks,
Adam
|
Folks,
Anyone is interested in testing 10.130 version for JS8CALL? Beta testing is required as JS8CALL activity is low here.
Thanks,
Adam
|
Folks,
I did ask my crystal supplier about the possibility to customize an AT cut crystal for 50.313MHz. The answer is no, not even for an overtone type. It seems that a simple crystal controlled radio is not possible for 6m. 在 2019年5月22日，上午7:54，Adam Rong via Groups.Io < rongxh@...> 写道：
toggle quoted message
Show quoted text
Tim,
Thanks, this is something that we can do.?
Thanks, Adam I got the idea from a Youtuber....(TRXBench) and tried it on a cheap Xverter and it seems to work OK. Why not try soldering a PTC resistor to the crystal to help stabilize it? It would be a very cheap TCXO.....It would NOT be an industry standard of course but? it might work well enough. Just a thought.
Tim - K5DEZ
--
|
|
|
Re: IMD performance of D4D
Should jumper wires be installed in place of C20 & C23 after they are removed?
|
Re: IMD performance of D4D
The D4D works great with my LDG Z-817 auto antenna tuner.?
73!
Jim - KH2SR
|
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: D4D kit manual 0523.pdf
Uploaded By:
Adam Rong
Description:
2nd preview version of D4D full manual. A lot of information and photos are added. This is very close to the formal release in a few days.
You can access this file at the URL:
/g/crkits/files/D4D%20Kit%20Documentations/D4D%20kit%20manual%200523.pdf
Cheers,
The Groups.io Team
|
Tim,
Thanks, this is something that we can do.?
Thanks, Adam
I got the idea from a Youtuber....(TRXBench) and tried it on a cheap Xverter and it seems to work OK. Why not try soldering a PTC resistor to the crystal to help stabilize it? It would be a very cheap TCXO.....It would NOT be an industry standard of course but? it might work well enough. Just a thought.
Tim - K5DEZ
|
I got the idea from a Youtuber....(TRXBench) and tried it on a cheap Xverter and it seems to work OK. Why not try soldering a PTC resistor to the crystal to help stabilize it? It would be a very cheap TCXO.....It would NOT be an industry standard of course but? it might work well enough. Just a thought.
Tim - K5DEZ
|
Re: IMD performance of D4D
Gang,
Follow up on this IMD topic:
Two domestic customers reported that D4D won't work with automatic tuner very well. One customer fixed it by switching off power supply of the tuner, the other has no fix yet. I guess it is related with IMD products. The automatic tuner will detect signal frequency and tune to the best point, but with strong IMD products, the auto tuner just failed to work.
Thanks,
Adam
|
Folks,
I have updated PayPal with all the tracking numbers. Orders on May 18 and later will be shipped next Monday. I shipped by post office with tracking, so you can track it on your local post office web site in a few days. For instance, US guys can track on USPS tracking site at?
You can also track on EMS web site in China here:
Normally it will take 10-20 days, so give it some patience and you will get it anyway.
Thanks, Adam
On Tue, May 21, 2019 at 9:19 AM Adam Rong via Groups.Io <rongxh= [email protected]> wrote: Folks,
I just shipped three boxes yesterday to my shipping agent and today they will ship to worldwide. The backlog is not cleared so I will ship some more next Monday. After shipping, I will update tracking number in PayPal.
The full manual preview draft is already in the files section. I will take time to improve it this week. You will see a brand new version when you get the kit.
Thanks,
Adam
|
Greg,
It could be challenging due to thermal drift of the crystal. A TCXO is very expensive to customize. However, we can give it a try to build a sample.
toggle quoted message
Show quoted text
Hi Adam,
congrats on fantastic product idea!
I checked the archive and did not find the answer so created new topic: did you consider making a 6m version of the D4D TRX? As most of the traffic on the "magic band" is FT8 it would be perfect device to take for travel - combined with Raspberry Pi and small, portable antenna...
If possible - one for me please!
73 de DL3GJ
Greg
|
Hi Adam,
congrats on fantastic product idea!
I checked the archive and did not find the answer so created new topic: did you consider making a 6m version of the D4D TRX? As most of the traffic on the "magic band" is FT8 it would be perfect device to take for travel - combined with Raspberry Pi and small, portable antenna...
If possible - one for me please!
73 de DL3GJ
Greg
|
Folks,
I just shipped three boxes yesterday to my shipping agent and today they will ship to worldwide. The backlog is not cleared so I will ship some more next Monday. After shipping, I will update tracking number in PayPal.
The full manual preview draft is already in the files section. I will take time to improve it this week. You will see a brand new version when you get the kit.
Thanks,
Adam
|
Folks,
Anyone has access to this page?
It seems new but I am curious about the design concept.
Thanks, Adam
|
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the [email protected]
group.
File: D4D kit manual.pdf
Uploaded By:
Adam Rong
Description:
Preview version of D4D full manual. Still lots of work to do, but I am posting here for comments.
You can access this file at the URL:
/g/crkits/files/D4D%20Kit%20Documentations/D4D%20kit%20manual.pdf
Cheers,
The Groups.io Team
|
Re: IMD performance of D4D
Gang,
Compared with 2nd and 3rd harmonics, the adjacent channel IMD products are higher. I did try to attenuate the input audio and it will improve but the result was not so satisfying. In this way, I have decided to remove C20 and C23 to change the LPF from elliptical to regular filter. It will improve the impedance matching with the antenna at the cost of higher 2nd harmonics. I will add this note into the full manual.
Beta testers, please remove C20 and C23 as well.
For serious builders, please follow this page to try:
https://pa3csg.nl/?page_id=40
Thanks,
Adam
|
Jim
Greg DL3GJ