Date   
Input voltage for HT-1A?

K9DRP
 

I just picked up several 4 cell holders for making a battery pack with
18650's, and a supply of used cells. But fully charged cells make for
an initial voltage of 16.7 or so volts.

Do I dare connect my HT-1A to this much voltage?

73,

Don, K9DRP


--
"I reckon. Therefore I am."
Don Pine, K9DRP
donpine@...
donpine@...
217-826-1111

Re: Z-match Antenna Tuner on Choc perfboard

Adam Rong
 

Folks,

I have a WeChat group for Chinese domestic hams. I just kitted a few Z-match tuner board kits for domestic hams at the parts price. It is fun to build together.

GQRP club has a great manual for it and we are following this:
http://www.gqrp.com/ATUmanual.pdf

Thanks,
Adam

Re: D4D low power output

Adam Rong
 

250-260mA is normal for 20m.

Thanks,
Adam

On Sat, Aug 24, 2019 at 3:01 AM Fernando S <fsclavo@...> wrote:
I tested my 20m kit and with power bar on max, it draws about 250~260 mA at 12v, are those value normal?



--
Thanks,
Adam Rong

Re: D4D low power output

Fernando S
 

I tested my 20m kit and with power bar on max, it draws about 250~260 mA at 12v, are those value normal?

Re: D4D TX power

Adam Rong
 

The mods are good enough. Now you have the flexibility to pursue better IMD if you inject audio just above VOX trigger point, or higher RF output if you increase audio.

Thanks,
Adam

On Fri, Aug 23, 2019 at 10:27 PM Fernando S <fsclavo@...> wrote:
Thanks for the fast response Adam!
I did KD1JV diode mod (the left one on your photo below), and replacing C5 by the provided 105 capacitor.
Is there any other recommended mod? With the mods I made, the power needs to be calibrated just as manual says? (I doesn't have a power meter).

0.jpeg


El vie., 23 ago. 2019 a las 11:16, Adam Rong (<rongxh@...>) escribió:
Congratulations! 600mV is the threshold to trigger the VOX. However, about 50mV is the point to overdrive NE602 per KD1JV. That's why I recommend a modification to improve IMD. Rule of thumb for acceptable IMD: Decrease the audio input until you find the RF output becomes about half.

Thanks,
Adam



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Thanks,
Adam Rong

Re: D4D TX power

Fernando S
 

Thanks for the fast response Adam!
I did KD1JV diode mod (the left one on your photo below), and replacing C5 by the provided 105 capacitor.
Is there any other recommended mod? With the mods I made, the power needs to be calibrated just as manual says? (I doesn't have a power meter).

0.jpeg


El vie., 23 ago. 2019 a las 11:16, Adam Rong (<rongxh@...>) escribió:
Congratulations! 600mV is the threshold to trigger the VOX. However, about 50mV is the point to overdrive NE602 per KD1JV. That's why I recommend a modification to improve IMD. Rule of thumb for acceptable IMD: Decrease the audio input until you find the RF output becomes about half.

Thanks,
Adam

Re: D4D TX power

Adam Rong
 

Congratulations! 600mV is the threshold to trigger the VOX. However, about 50mV is the point to overdrive NE602 per KD1JV. That's why I recommend a modification to improve IMD. Rule of thumb for acceptable IMD: Decrease the audio input until you find the RF output becomes about half.

Thanks,
Adam

D4D TX power

Fernando S
 

Hi!
I finally assembled my kit in a couple of hours, and I'm very happy with it.
Related to TX power, I read on the manual that needs to be set just at the minimum level that triggers the relay stably, so how much power is not being used before reaching an overdriving level? Is there any rule of thumb to raise the power a few db when minimum stably triggering level was found?

Thanks!

Re: HT-1A magic modification

Adam Rong
 

Someone asked me what is the secret key. How many keys are on the front panel? Try and it won't hurt.

Thanks,
Adam

Re: HT-1A magic modification

Adam Rong
 

Press and hold a secret key and power on. Check the splash screen for HT-1a instead of HT-1A and now you are good to transmit on 10MHz band before power off.

The spur and sensitivity of 10MHz is not the best, so use it at your own risk.

Thanks,
Adam

Re: HT-1A magic modification

K9DRP
 

Yes!

73,

Don, K9DRP

HT-1A magic modification

Adam Rong
 

Folks,

It is a HT-1A!
https://bbs7.sekkaku.net/bbs/upfile/qrp--1566139551-675-497-470-111.jpg

You want to know how?

Thanks,
Adam

Comparison table of FT8 capable QRP radios by JL1KRA

Adam Rong
 

Folks,

It is in Japanese, but you can figure out the major spec difference among our D4D and the other two radios. Thanks to the efforts from JL1KRA.
https://bbs7.sekkaku.net/bbs/upfile/qrp--1566059680-704-519.jpg

Our D4D is a simple radio kit for greater fun building, operating and modifying.

Thanks,
Adam

Re: D4D 20m kit for sale

bleepingbeep
 

The kit has been sold.

Jerry AA6KI

Re: D4D 20m kit for sale

Bryan Brauer
 

I will take it.  Is it pristine? How do I pay?
Bryan B. Brauer, PE
Consulting Engineer


On Sun, Aug 18, 2019 at 7:22 AM bleepingbeep <bleepingbeep@...> wrote:
Thanks for that comment, Adam.  The kit looks very nice indeed, but I recently did a reality check.  Too many unbuilt kits on my hands, that's all.

Jerry AA6KI

Re: D4D low power output

Nicholas Triantafyllou
 

Re-wound the toroid and all working perfectly :-)

Re: D4D 20m kit for sale

bleepingbeep
 

Thanks for that comment, Adam.  The kit looks very nice indeed, but I recently did a reality check.  Too many unbuilt kits on my hands, that's all.

Jerry AA6KI

Re: D4D 20m kit for sale

Adam Rong
 

35 USD would be quite good price as I have raised shipping.

On Sun, Aug 18, 2019 at 9:59 PM bleepingbeep <bleepingbeep@...> wrote:
Still available.  A guy said he would take it, but  he disappeared into the woodwork and has not responded to my email.



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Thanks,
Adam Rong

Re: D4D 20m kit for sale

bleepingbeep
 

Still available.  A guy said he would take it, but  he disappeared into the woodwork and has not responded to my email.

Shipping and service policy change

Adam Rong
 

Folks,

I've updated the web site to show the change of the shipping and service policy. Please view:
http://crkits.com

Thanks,
Adam