And for some SDR stuff I've done in the past, I've also used some Mini Circuits Amplifiers. Depending on what you're trying to do, there should be commercial solutions, or designs you can roll on your own, out there. Andrew > On Sep 1, 2017, at 8:05 PM, Ron Economos <w6rz(a)comcast.net> wrote: > > Not cheap, but I'm using a Kuhne amplifier for 70cm. > > https://www.kuhne-electronic.de/funk/en/shop/industrial/prof-power-amplifie… > > You can order it with a 40 dB gain option. Also, hams can order industrial equipment from Kuhne no problem. > > Here it is outputting 2 watts average power. This is DVB-S2 8PSK. The spike on the right is the DC offset of the B210 shifted out of the passband. > > http://www.w6rz.net/2ws2.png > > and 4 watts. The PAPR of DVB-S2 8PSK is about 4.6 dB, so the PEP is around 12 watts. > > http://www.w6rz.net/4ws2.png > > Ron W6RZ > >> On 09/01/2017 06:36 PM, David Ranch wrote: >> >> Very interesting project there Ron and thanks for sharing! One thing that I've been wanting to ask and you might be able to answer is: what options do people have to give something like this setup some real POWER? SDRs like an Ettus B200 are amazing but with a power output of only 10dbm (0.01w), it drastically reduces the real world uses of it. I know that lots of people say gain is cheap but to do it cleanly for say a full 8Mhz at say 10w is not exactly simple. I'll completely leave the legality of the spectrum width here to other folks. ;-) >> >> --David >> KI6ZHD >> >> >> >>> On 08/31/2017 03:06 PM, Ron Economos wrote: >>> Hopefully this isn't too far off topic. I've just completed testing of an OFDM modem using IP over DVB-T2. It uses an SDR transmitter and a commercial DVB-T2 receiver to implement the RFC 4326 Unidirectional Lightweight Encapsulation (ULE) for Transmission of IP Datagrams over an MPEG-2 Transport Stream (TS). ULE is supported in the Linux kernel for DVB receivers. >>> >>> https://tools.ietf.org/html/rfc4326 >>> >>> It's a full-duplex modem capable of up to 50 Mbps (in both directions) in an 8 MHz bandwidth. The current test bed consists of an Ettus B200 SDR transmitter, PCTV 292e DVB-T2 USB receiver, Kuhne down converters for 13cm and 9cm, Microlab BK-26N diplexer and RFSpace TSA600 Vivaldi antenna. >>> >>> http://www.w6rz.net/IMG_0119.jpg >>> >>> http://www.w6rz.net/traceroute.png >>> >>> The transmitter is based on the DVB-T2 transmitter in GNU Radio and uses this OOT module for the ULE protocol. >>> >>> https://github.com/drmpeg/gr-ule >>> >>> To reduce the latency, I've merged the DVB-T2 blocks to avoid having so many buffers between blocks. >>> >>> https://github.com/drmpeg/gr-dvbt2ll >>> >>> Current test frequencies are 2305 and 3429 MHz with an 8 MHz bandwidth. The bit-rate is 28.6 Mbps (symmetrical). >>> >>> It's intended to replace commercial WiFi equipment for amateur WAN interlinks. >>> >>> Advantages: >>> >>> 1) Full-duplex. Adding power amplifiers, preamps, diplexers/duplexers is easy. >>> >>> 2) Frequency agile. Can work on any band above 420 MHz. 70cm through 5cm direct TX from the SDR and millimeter frequencies with an up-converter. >>> >>> 3) Bandwidth agile. 5, 6 ,7 and 8 MHz bandwidths. >>> >>> 4) May be legal on 70cm. Although I haven't implemented it yet, a small portion of the bandwidth can be used to send a low-rate video stream (for example, a still picture of your call sign for ID). This would classify the emission as digital ATV, not data. >>> >>> Disadvantages: >>> >>> 1) Latency is a bit high. It's currently 100 ms (200 ms round trip). This is a function of buffering in GNU Radio and the USB 3.0 connection to the SDR. An FPGA implementation of DVB-T2 and a different SDR architecture could solve this. >>> >>> 2) Cost. It's difficult to compete with commercial WiFi equipment. However, lower cost components can be used instead of the "Cadillac" test bed I constructed. For example, a ADALM-PLUTO at $99 could be used instead of the Ettus B200 for transmit. Two antennas instead of a diplexer and lower cost down-converters than the Kuhne units. >>> >>> 3) Requires a Linux computer to run it. An Odroid XU4 may be adequate, but I haven't tested it. >>> >>> 73, >>> >>> Ron W6RZ >>> >>> >>> _________________________________________ >>> 44Net mailing list >>> 44Net(a)hamradio.ucsd.edu >>> http://hamradio.ucsd.edu/mailman/listinfo/44net >> >>