LimeSDR as a Amateur Radio Transciever


#21

The company HobbyPC sell a band pass filter for 2M, 1.25M or 70cm for 20$ each that can handle 20W … I have some and they are more than adequate … I use a low pass filter after my VHF amp because it outputs 100W with roughly 10mW drive (single block amp with bias control for SSB)

https://hobbypcb.com/products/uhf-vhf-radio/144mhz-band-pass-filter


#22

Do you guys have any updates on your amped up limesdr? I’m very interested in hearing how it worked out. I’d like to make an HF rig using a limesdr.


#23

I have had several projects going & haven’t gotten back to it. BUT, I picked up an FT-857D chassis, with a blown driver. The PA deck is fine. Once I figure out the signaling into it, I will slap it all together. It just has a TX input & RX output, along with LPFs, BPFs, Diplexers & the such. Perfect.

Ed


#24

I have ordered two of the Power Amplifier Kits and heatsinks and waiting for their arrival.
Do you have the assembly instructions? I cannot find them online and the link given goes
off to some other place.

I am in the process of putting parts together for my radio. LimeSDR + BeagleBoard X15.


#25

This is how looks 2m band today in KN05AD (its is contest time, not sure which one):


SDR device is LimeSDR-Mini but for now only RX. In my frontend RX preamplifier is with PGA103+ with additional helical BPF. For TX my plan is to build 30W PA kit (https://www.minikits.com.au/electronic-kits/rf-amplifiers/rf-high-power/RA-VHF-Amplifier) which will complete setup for 2m. Overall very cheap 2m SDR.


#26

@rkadrmas,

I purchased my amplifier reassembled with the heatsink - so I don’t have any assembly instructions but the seller has to (according to what they have on EBay).

73 de Marty, KN0CK


#27

I’m setting up my Lime for HF. I am trying to work out a box for it all. It will include a Mini ITX motherboard, filter board, switching board and small amp.

The amp has 2 - 3 watts output. Should that be moved far away from the Limesdr ? I was thinking of having the Amp right under the Lime (to save space) but worried about high levels of RF getting into the receiver and potentially overloading it ?


#28

Hi, I also have one of these. Did you try it? Did it work? What TX gain settings did you use?


#29

Hello everyone,

I finally got my amateur radio call sign (R2AUK). Although I have Yaesu FT-891 I thought it should be fun to make a few QSO with LimeSDR. One thing I don’t quite understand though - can I somehow use the same antenna for both TX and RX with LimeSDR? Considering that SWR of my antenna is far from 1:1 just transmitting 45W through the amplifier doesn’t sound like a good idea. And even if I use two antennas, one for RX and another for TX they will be quite close to each other and the effect could be the same.


#30

The assembly and tuning instruction can be found here https://www.algissalys.com/tech-notes/projects-45w-ssb-am-linear-cw-fm-power-amplifier-hf However please note that your version of the PCB may differ a little bit.

Also Vladimir Karpelyanskiy (R2AJI) recorded two videos of assembly of this amplifier:

The language is Russian. If something is not clear in the videos I will be happy to translate.


#31

If you would like half duplex on the same frequency’s you could use a antenna switch (rx/tx) on a GPIO.
For full duplex u’ll need a duplexer/diplexer which only works on different frequency 's.