Re: R3500D - QSY to 160m Top Band

#5197

Thanks Adam,

?

I'll give it a shot.

?

John

Re: R3500D - QSY to 160m Top Band

#5196

开云体育

John,

The LO has enough margin to cover 1.81 to 1.86 MHz. It said 1.75-1.80 because it was to cover 3.5-3.6 at half frequency.

Thanks,

Adam

在 2025/5/12 23:17, John GM4JRT via groups.io 写道:

Show quoted text

Hello all,

?

Has anyone converted the R3500D DF receiver for Top Band (1.81 to 1.86 MHz)?

?

I see the SDR Kits manuals mentions the following on that last page ():

?

"Note 3: For 1.8 MHz Operation fit additional 150pF capacitor in parallel with C3 and a 39pf
capacitor in parallel with CT. Oscillator Frequency is now the same as Receive Frequency."

?

The problem is the LO runs from 1.75 to 1.80 MHz so just outside the 160m band.

?

Any pointers or suggestions welcome.

?

?

73

John GM4JRT

R3500D - QSY to 160m Top Band

#5195

Hello all,

?

Has anyone converted the R3500D DF receiver for Top Band (1.81 to 1.86 MHz)?

?

I see the SDR Kits manuals mentions the following on that last page ():

?

"Note 3: For 1.8 MHz Operation fit additional 150pF capacitor in parallel with C3 and a 39pf
capacitor in parallel with CT. Oscillator Frequency is now the same as Receive Frequency."

?

The problem is the LO runs from 1.75 to 1.80 MHz so just outside the 160m band.

?

Any pointers or suggestions welcome.

?

73

John GM4JRT

Re: User Manual for R3500

#5194

Thanks for sharing.

Thanks,
Adam

Show quoted text

在 2025年5月11日，08:13，YT9TP - Pedja via groups.io <yt9tp@...> 写道：

?I wanted to have simple User Manual for this device, but all I could find was more oriented toward kit building. So I rearranged text found at  to make simple two page User Manual.

It is in attachment.

<r3500-user-manual.pdf>

User Manual for R3500

#5193

I wanted to have simple User Manual for this device, but all I could find was more oriented toward kit building. So I rearranged text found at  to make simple two page User Manual.

It is in attachment.

r3500-user-manual.pdf

Re: Holiday and Pixie 20m kit

#5192

开云体育

Thanks, JP. The weather is nice and I shot some nice photos for birds.

I noticed that import duty is effective for US guys now. Hopefully the customs clearance will go smoothly. It is advised that you guys provide telephone number so I can put on the shipping document.

During the holiday, I have updated some documents and the web site. You can check out what's new.

Thanks,

Adam

在 2025/5/2 7:42, JP McGinley via groups.io 写道:

Show quoted text

Adam,

? Have a great holiday. Hope the weather is beautiful for your time off.?

JP

KA3BWP

File Notifications #file-notice

Group Notification

#5191

The following items have been updated in the Files area of the [email protected] group.

/ADT/ADT Kit Assembly Manual 20250504.pdf

By: Adam Rong <rongxh@...>

Description:
Kit Assembly Manual in English, added 6m modification

The following items have been added to the Files area of the [email protected] group.

/ADT/ADT_V1.1.ino

By: Adam Rong <rongxh@...>

Description:
Source code V1.1 for ADT - Added 6m modification support

File /PIXIE2023/CPK1 Mod to 20m.pdf uploaded #file-notice

Group Notification

#5190

The following items have been added to the Files area of the [email protected] group.

/PIXIE2023/CPK1 Mod to 20m.pdf

By: Adam Rong <rongxh@...>

Description:
Instructions to modify Pixie2023 from 40m to 20m.

Re: Holiday and Pixie 20m kit

#5189

Adam,

? Have a great holiday. Hope the weather is beautiful for your time off.?

JP

KA3BWP

Holiday and Pixie 20m kit

#5188

Guys,

May 1 - 5 is a holiday here and I will go for some birding, so shipping will be paused. However, I will ask if someone else will need Pixie 20m kit since I have decided to customize for some customers. If you want it, please order a 40m version and leave your message 20m, and I will ship a 14060 version.

Thanks,

Adam

Re: ADT 6m experiments

#5187

Ahh ok Adam, i do have some of those, i shall give it a try. Cant remember what the cutoff frequency?was for those, think its 500Mhz. Before i was experimenting in class E with mofets, i couldnt get reliable results with transistors. Maybe it was my loading coil not right.

Thanks again for your work on this.

6m is the only band i have nothing for. There are no kits apart from the six box. Would be cool to see some activity in this area of our bands with qrp.

Nigel ZL1NAY?

Best Regards,

Nigel Young

Show quoted text

On Mon, 28 Apr 2025, 10:22 am Adam Rong via , <rongxh=[email protected]> wrote:

Hi Nigel,

I didn't use the through hole part. Instead, I used the C3357 SMD which is ideal for 5V.

Thanks,

Adam

在 2025/4/28 1:15, Nigel Young ZL1NAY via 写道:

Well done Adam, I was considering doing the same with my original board.

I would be interested to know which transistors you tried for the finals. I can't think of any small package through hole that would push 150mw at vhf, i did do some experiments using CB radio finals in class E driving it with a sig gen. Didnt get as far as a filter though.

Nigel ZL1NAY?

Best Regards,

Nigel Young

On Mon, 28 Apr 2025, 2:13 am Adam Rong via , <rongxh=[email protected]> wrote:

Guys,

I did some experiments to convert ADT to 6m and the result was very positive. With a modified filter board, I got near 150mW output which is not bad. The filter is simple but effective.

--

Thanks,

Adam Rong

Re: ADT 6m experiments

#5186

开云体育

Hi Nigel,

I didn't use the through hole part. Instead, I used the C3357 SMD which is ideal for 5V.

Thanks,

Adam

在 2025/4/28 1:15, Nigel Young ZL1NAY via groups.io 写道:

Show quoted text

Well done Adam, I was considering doing the same with my original board.

I would be interested to know which transistors you tried for the finals. I can't think of any small package through hole that would push 150mw at vhf, i did do some experiments using CB radio finals in class E driving it with a sig gen. Didnt get as far as a filter though.

Nigel ZL1NAY?

Best Regards,

Nigel Young

On Mon, 28 Apr 2025, 2:13 am Adam Rong via , <rongxh=[email protected]> wrote:

Guys,

I did some experiments to convert ADT to 6m and the result was very positive. With a modified filter board, I got near 150mW output which is not bad. The filter is simple but effective.

--

Thanks,

Adam Rong

Re: ADT 6m experiments

#5185

Well done Adam, I was considering doing the same with my original board.

I would be interested to know which transistors you tried for the finals. I can't think of any small package through hole that would push 150mw at vhf, i did do some experiments using CB radio finals in class E driving it with a sig gen. Didnt get as far as a filter though.

Nigel ZL1NAY?

Best Regards,

Nigel Young

Show quoted text

On Mon, 28 Apr 2025, 2:13 am Adam Rong via , <rongxh=[email protected]> wrote:

Guys,

I did some experiments to convert ADT to 6m and the result was very positive. With a modified filter board, I got near 150mW output which is not bad. The filter is simple but effective.

--
Thanks,
Adam Rong

Re: pixie net on last wednesday of every month

#5184

N/A means remove it?

Re: CPK-1 2023 output power

#5183

Thank you very much! I appreciate

ADT 6m experiments

#5182

Guys,

I did some experiments to convert ADT to 6m and the result was very positive. With a modified filter board, I got near 150mW output which is not bad. The filter is simple but effective.

--

Thanks,

Adam Rong

Re: CPK-1 2023 output power

#5181

Patrick,

See this post for 20m mod.

/g/crkits/message/4844

Show quoted text

On Sun, Apr 27, 2025 at 10:00?PM Patrick via <pkummer83=[email protected]> wrote:

Thank you for your reply. I did use two 20dB attenuators while doing the measurements. Ok, I will try to change the transistor and power the Pixie with 12V.?

Meanwhile I was looking for informations to convert the Pixie to the 20m band. I found a blog but there is a different Pixie model in use. Do you have any suggestions?

--

Thanks,

Adam Rong

Re: CPK-1 2023 output power

#5180

Thank you for your reply. I did use two 20dB attenuators while doing the measurements. Ok, I will try to change the transistor and power the Pixie with 12V.?

Meanwhile I was looking for informations to convert the Pixie to the 20m band. I found a blog but there is a different Pixie model in use. Do you have any suggestions?

Re: CPK-1 2023 output power

#5179

Hi Patrick,

I have replied your comments to my video. Your result is very normal.?My tinySA shows -19.7dBm because I have attached a -40dBc attenuator. To increase the output, you can consider replacing the final transistor to 2N3886 or similar, or simply increase the voltage of the power supply to 12V.

Thanks,

Adam

Show quoted text

On Sun, Apr 27, 2025 at 8:43?PM Patrick via <pkummer83=[email protected]> wrote:

Hello everyone!

?

Just finished my first Pixie built. I checked the output with my tinySA ultra. The Pixie produces an output power of 22dBm (about 15mW) and is stable at a frequency of 7.03MHz with my chosen crystal. I used a 9V block battery fully charged while measuring. I think this is a little bit too low. In Adam Rongs built video on YT he got an output of 29dBm (so about 800mW). Any suggestions?

?

Thanks for your replies

?

73 de OE8ZZZ - Patrick

--

Thanks,

Adam Rong

CPK-1 2023 output power

#5178

Hello everyone!

?

Just finished my first Pixie built. I checked the output with my tinySA ultra. The Pixie produces an output power of 22dBm (about 15mW) and is stable at a frequency of 7.03MHz with my chosen crystal. I used a 9V block battery fully charged while measuring. I think this is a little bit too low. In Adam Rongs built video on YT he got an output of 29dBm (so about 800mW). Any suggestions?

?

Thanks for your replies

?

73 de OE8ZZZ - Patrick