Software Defined Ham Radio

I have my radio setup for auto band switching. After Hurricane Matthew tore down my antennas last month I've been in a rebuilding mode. Auto band switching means my amp and antennas band follow my transmitter which is a Flex 6700

All of the antenna cables from the 6700 are represented on a patch panel which resides next to my left leg, screwed to the table underneath the table top. My amps, tuners, power meters, and antenna switch controller all present jacks on my patch panel in a 4 x 8 matrix. My 6300 and 6500 Flex are also represented on the panel. I have a separate panel for switching radio amp signals to my various amps, so its quick work to join The 6700 sends its RF to join a transceiver to a amp to a antenna. My 6700 generally feeds my ALS 1300

That amp generally feeds my MFJ-998

And that feeds either my RCS-4 antenna switch or my G5RV.

It allows me through software and to choose my antenna. I modified the RCS-4 to automatically band follow my radio and the 4 positions allow me to cover 160M, 80M, 40M, and 20M with resonant verticals and I can tune 80M to cover 30M with little loss, and 40M to cover 15M. 80M will also load on 60M efficiently and 12M and 10M will load. 17M is a little flakey. My antenna previous to Matthew was a 65ft vertical, a 130ft inv-L, a half wave 40M end fed vertical and a 5/8 wave on 20M all over 4K feet of ground plane. It was a flame thrower. Today I've rebuilt with a 33 ft vertical using fiberglass telescoping pole. My pole is made from some parts that are very light but strong. I don't use those joiner things just a couple hose clamps, one on the bigger pole to help keep the end from splitting and then some tape on the telescoping piece and another hose clamp compressing the tape. Makes a perfect reliable joint. 2 wires go up the pole, one for 40 and another for 20. To support the pole I pounded in a steel mast like the kind used to telescope for a TV antenna. The vertical slips over the mast and it is both vertical and strong. I have a second shorter pole which starts my 80 and 160 antennas to about 16 feet and then those wires continue up to a branch on a tree where the L goes out to a second tree. These antennas can be lowered in 1 minute.

DXlab is set up so if I click a spot like YO3APJ on 3505, every goes to 3505 and I have a couple tuning macros which allow the tuner to touch up the tuning, and I'm ready to call. I have a macro which puts my transmitter via XIT UP THE BAND by 2 khz to keep from tuning on the DX! I hate that. Not only is it inconsiderate, it shows the tuner upper is a moron since it would be better to tune where you are going to transmit as in the case of a pileup. My setup can tune at about 8 watts of power since the amp is no tune all I have to do is match the antenna. For receive I can move the G5RV feedline from the tuner to the RX2 input on the 6700 and I also have a ALA-100 Welbrook active loop on rxB and I can choose any pair of the receive antennas with my diversity choice on the 6700. I loved the beam forming feature in the 5K and Anan, but I find the diversity setup in the 6700 to be very versatile when it comes to weak signal work. It's easy to write macros in DDUTIL to

click between antenna pairs and compare which pair has the best advantage. I still have a couple more antenna slots to add to the mix

I heard Adrian YO3APJ on calling CQ and working simplex and I'm still trying to see how the new verticals perform, so I gave him a call. Adrian gives honest reports so I knew it would be a good test. Came back as 599 "booming signal" (yep Adrian gives honest reports :) ). The antenna system seems to be shaping up pretty well. The bands have been hot but I seem able to couple adequately into the aether.

73 W9OY

Posted by W9OY at 3:08 PM

Off the North coast of Venezuela is a place called Carriacou Island and Ve7ACN has placed it on the air.

Easy shot from the US, big S9 signal and good op

73 W9OY

Posted by W9OY at 12:08 AM

VU7MS is on the air from the East Indian ocean.

This took forever. I started hearing him about 15:00 and it wasn't till 19:00 I finally worked him. Initially I was in competition with EU, Japan, and Russia but to soldier on. He was slowly but randomly skipping through the pileup sometimes moving, sometimes staying put. Eventually he had pity on NA/SA and managed to tame the rest of the world and give us a chance. Even so it took over an hour of calling and figuring out the pattern. Eventually I got him by tailending someone but moving up about 40hz. I had diversity going and it made all the difference on RX. My hat's off to the op for his tenacity and good habits.

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73 W9OY

Posted by W9OY at 7:13 PM

Now this is the way to go on a DX pedition! DL7KL is on from Diani Beach Kenya. My band noise on him was -107 dBm and his signal was only -105 dBm, but I was still able to work him in 2 calls. The band from Mims, FL is open to Africa and the Indian ocean tonight and the old trusty Flex is tearing it up!

Since I had my diversity antenna scheme hooked up, I turned it on and it turned a Q3 signal into a Q5 signal even though he was only 2 dB out of the noise. I've been chasing this guy for a while and it's the first time I heard him well enough to make contact. Good op and good ears. I'm having me some radio fun!

73 W9OY

Posted by W9OY at 7:28 PM

Tonight I worked 8Q7DV out in the Indian ocean on 40M. I was listening to 80M but could just tell he was in there. He came up on 40M was quite respectable. My 40M band noise is about -110 dBm tonight and 8Q7DV was -105dBm. I got him simplex in 1 call, and he soon went split

It was just at sundown and the terminator was flying over my head.

I decided to make a quick video to demonstrate diversity on the 6700. The 6700 creates a true spatial diversity between the 2 receivers. Its intent is to reduce fading. It is not beam forming like the F5K or the Anan. Those systems are not true diversity but accept one signal as I and the other signal as Q and then creates a plane of points with variable intensity and phase therefore creating a cardioid pattern. The Flex uses 2 signals which have relative independence with each other but are coherent and the signal is presented to the brain in a way that reduces fading.

You can see the diversity slice is slice H in the above pic and it has adjustment available for AGC-T audio AGC period (fast med slow) and the DSP functions. The bandwidth is matched on the 2 receivers and one RX is placed in the right ear and the other in the left. My antennas are a vertical a G5RV up about 55 ft and a Wellbrook ALA-100 loop. The dipole and the vertical are separated by about 170 ft and the vertical and loop by about 100 ft. The 6700 antenna switch is powerful enough to allow for up to 5 receiving antennas in a multiplicity of combinations so there are many permutations possible depending on your space. I made a video demonstrating. There wasn't a huge amount of fading on this station, but the system does make station readability more stable.

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73 W9OY

Posted by W9OY at 6:49 PM

I was listening to 30M and heard 5T9VB in Mauritania on the west coast of Africa. The terminator was about half way between us on a 4130 mile path

My band noise was near -117 dBm and he was peaking -114sBm or a little better with some QSB. I managed to work him in 2 calls. I've recently been involved in a conversation with Bjorn LI9IAA regarding the Flex 6K series vs the Anan radios in terms of feature set. The radios share some homology but in some respects the Anan in my opinion at least when using HPSDR is more of a variant of the Flex 5K rather than something akin to the 6000 series. To be sure the Anan/HPSDR is different than the F5K but I think it's implementation is more of a refinement of a 5K. I own both Flex and Anan and have a 5K, a 6300, a 6500 and a 6700 as well as a Anan 10. I had a 100D but decided to sell that radio.

Given the strength of 5T9VB at my QTH I thought it might be an ideal way to show how Flex is doing it's filtering. I'm using version 1.10.8.30 software. Flex has implemented a filter matrix that allows latency vs filter sharpness to be chosen depending on need and preference

Sharp filters have best S/N and QRM rejection whereas filters with less steep skirts have lower latency. Latency becomes important to operators who demand pristine QSK, whereas sharp skirts are important to those of us that require best S/N. The matrix allows you to tune your radio to your given or perceived needs. My needs are best S/N. I find QSK to be absolutely unimportant. If I want it it is available to me and I even have full duplex available if I want it.

I made a video of how the matrix works at various bandwidths and I added APF since Bjorn was interested in how APF works in the Flex.

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73 W9OY

Posted by W9OY at 5:04 PM

K7AR is on from Raivavae in French Polynesia from Nov 21 till the 28th. I caught him tonight on 30M

Nice signal. My band noise was -117 dBm and his signal was -111 dBm. He was alternating between all comers and EU which was nice. Good op, easy pattern to figure out, so he was in the log in just a few calls.

73 W9OY

Posted by W9OY at 10:44 PM