SDR Dongle Panadapter on a CB?

[Bow]

I have a couple extra CBs (who doesn't) and a spare SDR Dongle...

I have been looking at Panadapters and was wondering if anyone has used an SDR as a Panadapter on a CB radio... Export or normal FCC legal.

I believe you are required to wire it straight to the IF Output of the victim with Coax, and feed that coax straight into the SDR's antenna port.

I have used SDRs before, so I have the computer side mostly figured out, I guess my question is, how does one find the IF output on a given radio?

 

[Bow]

34 views... no inputs...

Hmmm...

 

[dave457]

As I recall joe dirt has done it, don't know if he's still around. Might want to pm him here or over at mauldroppers

 

[FredTx63]

543_Dallas (Forum member here) posted details about a modern AM only CB that he had an SDR connected to the IF on. You can probably find the thread if you search a bit. Or maybe he'll see this and chime in.

 

[Bow]

I have been searching the forum, probably using the wrong words...
I'll keep poking

 

[543_Dallas]

I'm not much help because I figured most things out by trial and error. If you can find the IF frequencies in the service manual set the sdr to that frequency and start probing around.

Use the first IF if you can so you get the most out of the panadapter. Lets say you tap somewhere near the 455 khz filter. Your panadapter view would be limited to the width of the filter.

It's been a few years and I can't remember the frequency of the IF I tapped on the uniden 78ltd. A sharp radio tech could look at a schematic and tell you pretty quick.

 

[fourstringburn]

If you can find one of these it works flawlessly on my Icom 7000. No mods required. Your basically grabbing the RX audio from the radio antenna port and putting that on the pan adapter display. That's all I use it for is to check signals on the bands.

You''ll have to rig up a PTT line but that shouldn't be difficult. This will keep your TX signal from blowing up your SDR receiver. The other thing to do is get an adapter from a PL-259 to BNC and a SO239 to a SMA or whatever the SDR antenna ports use.

There are audio ports on the Elad box but they aren't necessary depending on your application.

MFJ makes their version of this but the keyline didn't work like it should have so I sent it back.

That's all!

 

[FredTx63]

There's this thread, with a picture of the radio in question - but his Asymod board is covering the spot where his IF tap is soldered to: https://www.worldwidedx.com/threads/asymod-iii-schooling-snake-oil.241997/

It's "somewhere under that board" lol

 

[fourstringburn]

Here is the MFJ simpler version of the Elad box with no audio ports. Maybe the one I tried was defective and you'll have better luck.

This is the easy way to get your RX into a SDR with no mods to your radio, just use some RF adapters which are readily available.


https://www.mfjenterprises.com/Product.php?productid=MFJ-1708SDR

 

[unit_399]

Try Googling this. "SDR panadapter on a cb" lot of good hits and info

- 399

 

[500kpot]

I saw a homemade pan adapter today on a Cobra 29. It was a simple buffer circuit connected to the drain of FET1 or 10.695 metgahertz output before the signal goes into L4.

Then to an RTL-SDR HF converter connected to a RTL-SDR and the software tuned to 10.695 megahertz.


SSB and AM sounded great.

 

[kopcicle]

https://www.sdr-kits.net/PAT12A
Tap the 10.7 IF without loading it

 

[500kpot]

There was no loading of the IF. It made no difference if the adapter was installed or not. It is just an mpf102 buffer circuit, powered by the receive only 8 volt supply. .

Made from parts just "laying" around so the cost was practically zero. Okay, maybe one USD.

 

[W4KVW]

Pretty sure there are several videos on YouTube of it having been done with CB's.I remember seeing them somewhere & that would be my guess as to where I saw them.

SIX-SHOOTER

 

[500kpot]

It looks like many people on youtube just run the sdr on 27megahertz directly. I wonder why bother with the 10.695 megahertz adapter?