Custom RTL SDR

[KC8ESL]

I got sick of my SDR and the crappy antenna with a useless connector. I had a spare hammond project box laying around so I made something useful out of it.



This is the SDR with the case stripped (pulling it apart required no tools) and the connector de-soldered.



I prepped the end of the cable as such so it would fit into the PCB.




Coax (Gepco VDM230) is soldered.



The SDR case is closed. No modification needed in the plastic with the size of coax I used.



I used a Neutrik NAUSB connector (guts flipped backwards) and plugged the SDR directly into that. I also screwed a panel-mount BNC connector to the case and soldered the coaxial cable directly to the connector and had the shield tied to the screw with a ring terminal. This is not a pass-thru.

Side notes, the cable used was Gepco VDM230 (75ohm 3GHz bandwidth - that was the right size, don't care).

The RTL SDR fits very snug inside. Due to the 5 photo limit I couldn't show you that I have styrofoam holding the SDR tightly in place should it be dropped. All in all, the mod worked better than I could have hoped. Soon I will be placing this package into a larger box and sticking into the package a 15v DC injector with an on/off switch for a remote preamp and a 2 way passive splitter so I can plug my 396xt into the same antenna. The idea is that I can use the [insert model scanner here] to monitor control channels and have the SDR track when the MARCS-IP or any other system goes Phase II (if it ever does).

 

[SCPD]

Let me be the first to tell you thank you for posting this for others. I have also done a boatload of mods to the r820t's and e4000 chips.

Hi five. Good work on the shrink tubing.

I will give you one of my mods. Remove the blue led next to the ir receiver module and re-route it to the front or side of your hammond box.

 

[KC8ESL]

Yes, the next box will have 3 LED's and a switch on it.

This is a hobby. We need to treat it as such and let people add/modify our designs without taking offense to it. What works for me might work well for you but you like it a certain way. Then by all means, go for it! I am all about open-source.

 

[SCPD]

Buddy i'm all about open source. Keep us all in the loop with this project. You can also reply to your own thread and add more pictures

 

[KC8ESL]

Once I order the new box and parts to go in it, I will post more pictures of the mod process. I just think it's a cool idea to have the power injector for a preamp and a passive splitter inside the case. Less parts to consider outside of the box and makes for a cleaner install.

I am trying think of anything else I would want inside there before I purchase parts but so far, nothing comes to mind.

The only thing I could think of is a parallel input with an SO-239 connector on it should I want to use one of my ham radio antennas in the shack. Less adaptors is less loss.

 

[SCPD]

You might want to consider a FM-TRAP they are super cheap.

RadioShack FM Trap 1500024 | eBay

 

[KC8ESL]

One of the reasons I enjoy the SDR is broadcast DX. I'm not sure that would be on my list of internal parts for the new box. It would definetely be something to keep in my gig bag though should I need it.

 

[moonbounce]

looks like a cover goes on the top of the Hammond box which would seal the RTL dongle inside. My question do you have any concerns of the heat inside the box once it is up and running?

 

[KC8ESL]

The heat of leaving that box in the sun on a hot day concerns me more than the heat that the sdr generates. I doubt the dc injector will generate any significant heat either. Should it need it, I can always add a 12v fan using a LM7812 off of my 15v source. Don't forget that hammond metal enclosure is a heat sink in itself.

I've run that box as-is, lid on for several hours at a time. The temperature doesn't seem to change in the least. Is this a valid concern? Absolutely. I was concerned with that myself. The computer may need an additional heat sink because it runs HOT trying to crunch the numbers that the SDR feeds it.

 

[moonbounce]

Pardon me if I am wrong but the box would only act as a heat sink only if the cover of the usb dongle was laying up against the metal of the box so that it would radiate heat away from the dongle.

I see that the usb dongle in the picture is actually suspended kind of in midair so no heat will radiate from the body of the dongle to the metal body of the box. Instead the heat will remain inside the box. Also you mentioned that you are going to put styrofoam inside the box (unless you are talking about another box )which will act as an insulator and I am sure that will the dongle run even hotter.

The reason I bring this up is that my usb dongle sits on top of the case of my desktop and sometimes on my external backup drive and when it is on the external backup drive, it runs hotter. Anyways I just wanted to mention that.

Moonbounce

 

[KC8ESL]

The sdr board is already in a plastic case. It is in use all over the world in all forms of climate. If it doesn't burn up in the already-constricted space it's in, I doubt mounting it in a metal box will be worse for it. The only heat I've ever felt from it is the heat that blew out of the computer directly onto it. Once I used a 6ft usb extension the temp of the sdr was ambient room temperature.

I still agree, a valid concern.

 

[trunker101]

I got sick of my SDR and the crappy antenna with a useless connector. I had a spare hammond project box laying around so I made something useful out of it.


View attachment 42932
This is the SDR with the case stripped (pulling it apart required no tools) and the connector de-soldered.


View attachment 42933
I prepped the end of the cable as such so it would fit into the PCB.



View attachment 42934
Coax (Gepco VDM230) is soldered.


View attachment 42936
The SDR case is closed. No modification needed in the plastic with the size of coax I used.


View attachment 42937
I used a Neutrik NAUSB connector (guts flipped backwards) and plugged the SDR directly into that. I also screwed a panel-mount BNC connector to the case and soldered the coaxial cable directly to the connector and had the shield tied to the screw with a ring terminal. This is not a pass-thru.

Side notes, the cable used was Gepco VDM230 (75ohm 3GHz bandwidth - that was the right size, don't care).

The RTL SDR fits very snug inside. Due to the 5 photo limit I couldn't show you that I have styrofoam holding the SDR tightly in place should it be dropped. All in all, the mod worked better than I could have hoped. Soon I will be placing this package into a larger box and sticking into the package a 15v DC injector with an on/off switch for a remote preamp and a 2 way passive splitter so I can plug my 396xt into the same antenna. The idea is that I can use the [insert model scanner here] to monitor control channels and have the SDR track when the MARCS-IP or any other system goes Phase II (if it ever does).

This is awesome how much to have you do this mod for me?

 

[KC8ESL]

I'm not sure we are allowed to conduct business in the forums but I can tell you the parts alone minus the sdr stick are roughly $60. Hammond project boxes are no joke and the neutrik part NAUSB retails for about $16.

I can tell you that I would be happy to help you source parts for YOUR project and assist you however possible.

PM me for more info.

 

[N0IU]

I also want to commend you on a fine piece of work! For the time being, my dongle is just hanging off of the front of my PC (by using a short USB extension).

Even though I will soon qualify for membership in the QCWA, I have only just recently starting using a DVB-T dongle for SDR and this is the first thing to come along in quite a long time that I have been really excited about.

My next purchase will be an upconverter (most likely a Hamitup from NooElec) and my ultimate objective is to put the dongle and upconverter into one box and your project gives me some great ideas.

Thank you!

 

[Your_account]

@KC8ESL
I use 2 Chili Soup Cans and i put the smaller one into the lager and the Dongel inside.
That is much better then nothing and cost 0€ (if you eat the Food inside *gg*).

 

[KC8ESL]

Scott, I would consider the hamitup converter if I didn't have another sdr for hf already. Perhaps for ease of use could one day incorporate that into my setup. I have plans and parts to add a dc power injector and 2 way splitter so I can hook in my scanner to the same antenna with a 20 db LNA. If I can get my hands on a 10 db step attenuator that would also be a nice device to have inline as well. These will all be fitted into a larger Hammond enclosure and act as one cohesive piece. Perhaps I will drill out and blank over the attenuator so when I but it I will have it ready to go. If I ever add the Hamitup converter I will probably go all out and make it into a 2u rack chassis.

Your_account, would you mind posting a picture or two to this thread? I'm always interested in how the other guy is doing his thing

 

[Your_account]

You see just a Soup Can and 2 Wires (1x USB and 1x Antenna) there is no "magic" Connector or stuff like this.
My Pc is very noisy and it block that signal very good.

 

[SCPD]

My Pc is very noisy and it block that signal very good.

Awesome! I'm tempted to try this with an 8.4 ounce Red Bull can inside a 12 ounce soda can.

 

[Your_account]

I dont care about the temperature. I have 10Dongel at home so if some die i grap the next.
Someone say he put some Wegi Oil in the Can to cool it down. But i dont try it its to risky.

 

[Your_account]

@KC8ESL
So i have the same ideal like you but a much professional.
1) I found an German Company who sold that type of USB you use.
http://produktkonfigurator.schlegel.biz/produkte.php?artikel=27180

2) and an SMA Connector: SMA-Einbaubuchse, Flanschbefestigung, Lötausführung, 50