New Addition: Flex 6500

Going ‘All In’ with FlexRadio!

After working with the 6700 for a few weeks I decided it was time to replace my 6300 back-up radio, with a 6500. The 6300 served me well during my introduction to the 6000 series hardware and SmartSDR. It sold quickly (thanks Leo) and the repaired 6700 and CPO 6500 will be here as soon as the repair is complete. After working my way through all the used listings online, I couldn’t find an available unit for much less than the cost of a  Certified Pre-Owned 6500 with a 1 year warranty. It made the most sense to buy the CPO from Flex. And in light of my experience with the drifting CPO 6700, I decided not to take any chances. The new addition Flex 6500 should complete my radio hardware requirements for the foreseeable future.

The “Business End” of the Flex 6500

Dedicated to Digital

The plan is to purchase a Comet CHA-250B vertical antenna for use with the 6500, and dedicate the radio to digital modes. I’ll experiment with some new (for me) modes like FT8 and PSK and decide at some point which modes to settle on. And of course, I will continue with SSTV and EasyPal.

The purchase of the Flex Maestro freed up this little Gigabyte Brix PC that I used to run SmartSDR in another area of the house.

I need to find a use for the Brix PC!

I’m going to pair up the Gigabyte Brix PC with the 6500 and see how it keeps up. The Brix ran SSDR ok, but the wireless connection was not the greatest. In the new setup, the Brix will be located next to the router. The question is whether or not several programs will run alongside SSDR. We’ll see…

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Flex 6700, 6500, LP-500, Arriving Soon!

I’m now #2 on the LP-500 waiting list, so it should be arriving soon. It looks like they fulfill about 10 units per week, so I’m pretty confident I should have mine next week . I joined the waiting list in May 2018. This is one of the nice finishing touches being installed for 2018.

Flex Sales and Service Dept.

I was contacted by Flex Service to let me know they expected to get to my 6700 repair  one day this week. As soon as it is ready, it will be shipped back along with the Certified Pre-Owned 6500 that I just purchased. Both these units will be arriving soon and it looks like delivery should coincide nicely with the LP-500

These three units more or less complete the shack. No more improvements for a while. It’s time to get all the shack furniture put back together and get back on the air and get to work!

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Flex 6500/6700 Install

FlexRadio 6500 and 6700 On the Air

Flex 6500 and 6700 On the Air!
Flex 6500 and 6700 On the Air!

The Flex 6700 is back from repair, and the frequency drift problem has been taken care of. The radio is now stable and able to decode FT8 and other digital signals. There’s no sign of drift on WWV. The Flex 6500/6700 were installed today, and are now in service on the air!

The new Flex 6500 will be dedicated to decoding the various HF digital modes. I plan to move the Live SSTV Cam over to the 6500 once I have the Comet CHA-250B installed.

Flex 6700 6500 installed
Just enough space left for the TelePost LP-500

The station monitor should arrive this week. I have just enough rack space left to fit the LP-500 between the 6700 and the SPE 1K-FA amplifier. I will install the LP-500 utilizing 4 couplers to enable viewing of amplifier linearity with a trapezoidal display on both channels of the amplifier.

Single channel amplifier configuration 

The illustration above shows the configuration for a single amplifier. Since the SPE 1K-FA has two inputs (one for each of the 6700’s SCU’s) I will duplicate this configuration for the second input/channel.

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Dead radio?

I was trying the FT8 digital mode for the first time on my new Flex 6500. The radio was in (full duty cycle) FT8 transmit at 100 watts into near perfect SWR when I heard a ‘pop’, after which, the radio would no longer power up.

I immediately assumed I had blown up the radio…

Yep, you could say I was a little ‘bent out of shape’. All I can say is, it’s a really terrible feeling. Mostly, I was angry at myself for having blown up the radio. Mega p1553d was more like it…

After regaining some composure, I noticed some of the other 12V gear, not in use at the time, was also off. So I pulled out the voltmeter, and sure enough (and much to my delight!) there was no DC on the power lead to the dead radio!

How Do You Spell Relief?

I immediately connected the radio directly to the power supply and started dancing when the radio powered up. RELIEF is not a strong enough word in this case.

As it turned out, I had blown a fuse in the MFJ power strip!

The culprit: 15A 32V fuse

Can’t blame MFJ for this one! This is what happens when you try to draw 25A through a 15A circuit. A rookie mistake.

Easy to replace….If I can find one!

A couple of local stores are showing them in stock. This is a 15A/32v fuse.

In an effort to take some of the load off the MFJ-1118 I will connect the two 6000 series radios directly to the power supply. The MFJ-1118 is not relied upon to protect the radios, and I now realize that having it inline with the radios is wholly unnecessary.

The most time consuming part of this problem was getting the power strip out of the rack! I had installed the MFJ power strip inside the rack behind the Flex 5000 and now realize it was a design flaw to have located it there.

After replacing the fuse, the MFJ-1118 will be mounted to the exterior side of the rack for easier access going forward.

OK, so by now, I’m sure you’ve figured out how I got myself into this situation!

In error, I had connected the Flex 6500 to a 15 amp circuit. While in full duty cycle transmit the radio requires 25 amps. Hence the pop!

I’ll replace the fuse, change my shorts, Hi Hi, and go on my way a little wiser.

UPDATE: Found the fuse at Home Depot, replaced the fuse and tie wrapped the MFJ-1118 to the side of the rack. Reconnected all the 12v gear, and everything is back together.

I should have mounted it here to begin with!

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Getting Started With FT8 WSJT-X

Flex 6500 with WSJT-X Software

FT8 activity via WSJT-X
FT8 activity via WSJT-X

WSJT-X has arrived! I purchased the Flex 6500 for exclusive use in digital modes. I have the 6500 configured to listen for SSTV (Slow Scan Television) signals and EasyPal digital transmissions on the 20 meter band. At the same time I’m running two instances of wsjt-x on other bands.

Making Contacts via FT8

After following the set up instructions, and getting the audio and RF levels correctly set, I was making contacts via FT8 ‘right out of the box’. I’m running the Flex 6500 barefoot (100 watts) into a Comet CHA-250B multiband vertical antenna on a test stand in my backyard. The results were immediate. One of the first few contacts I made via FT8 was DX with JA0IXW. Not bad!

I have been able to complete almost every contact I’ve attempted so I’m pretty confident my little digital setup is working AOK! I’m putting out a very clean 100 watt signal.

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EA4TX AS2X2 Antenna Switch

One Step Beyond SO2R

For all intents and purposes, my SO2R operation is self-contained. I use a Flex 6700 dedicated to SO2R operation. I’m operating through an SPE Expert 1K-FA amplifier. This allows using two TX antennas and a wideband RX Magnetic Loop antenna. I enjoy fully automatic operation utilizing one Flex SCU (Spectral Capture Unit) per TX antenna. Really a perfect setup! This configuration has now been thoroughly tested and fine tuned to my operating preferences. Battle tested in contest with more multi band contacts than was ever possible for me while working manually. (the M word). In comes the EA4TX AS2x2 switch to enhance station operation.

I can now freely operate on any band at any frequency, and always have the lowest SWR and the appropriate drive level set automatically. We all know nobody has time to wait around for you to tune up during a contest! You’ve got to be there or be square!

Flex 6500: Dedicated To Digital

Now that I have the SO2R contest station squared away, I’ve turned my attention to the Flex 6500. I have MMSSTV running on 14230, EasyPal on 14233, and two instances of WSJT-X running on any two of any of the other bands that may be open, 24/7. I can work digital modes back and forth between any two bands with a click of the mouse.

For that matter I can also TX from any of the running programs with a single click thanks to the Flex DAX TX feature that switches the TX slice automatically. Combine that with a multiband antenna, and the possibilities are endless!

Watch That Front End!

So now that the digital station is setup and running what’s the problem? Well it’s not a problem yet, but very well could be.

The Flex radios have some built-in protection for the front end of the radio, but it would not be wise to count solely on that feature for complete RX front end protection. In the SO2R setup I added an Array Solutions RXFEP on the RX only antenna to protect the RX when the amplifier is not in operation to switch the RX only antenna automatically. When the amp is off, I have an extra level of protection.

With the 6500 running 24/7 digital modes it would not be hard for me to imagine accidentally TX ‘ing at 1,000+ watts while forgetting the other radio is nearby in RX mode (aka an ‘Inband Radio’). It would just be a matter of time before this type of accident would take place. I could easily make this mistake, so I must add a level of protection against it. In a multi-transmitter environment this is a requirement.

EA4TX AS2X2 Antenna Switch

EA4TX 2X2 Antenna Switch

I researched several antenna switches for the purpose of disconnecting the Flex 6500 antenna when the SO2R contest station is transmitting. Keep in mind I need to be able to transmit 100 watts through the switch. I quickly learned that the the first two “RX Antenna Switches” were not intended for use where the second radio is also a transmitter. Instead they were designed to switch out a receiver only. You cannot transmit back through the second RX port. So the first two switches were eliminated.

I came across the EA4TX AS2X2 and found it could handle 200 watts. It is not an RX only switch, it is a two port switch designed for switching (or exchanging) two antennas (TX and/or RX) between two radios. I’ll only need one side of this switch as I only need to disconnect the Comet CHA-250B antenna, not necessarily switch it with another.

I purchased the EA4TX ARS-USB rotor controller and have been very happy with its quality and performance, so another EA4TX product is welcome. Yes, I saw the single star review. I’m not worried because I know DX Engineering stands behind what they sell, as pointed out in the review.

UPDATE: The AS2x2 arrived today and is now installed at the antenna input of the Flex 6500. Whenever the Flex 6700 is in TX, the antenna to the 6500 is disconnected. Better to be safe than sorry.

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Dedicated Digital Rig Pays Off!

Worth the Investment

Time spent building the digital side of the station is proving to be time and effort well spent. The dedicated digital rig is paying off big time, as DX contacts are coming in on all bands. The DX results are better than anticipated!

Flex 6500 Dedicated to Digital: Dell 7050 running WSJT-X, MMSSTV, EasyPal. Monitoring 24/7.

dedicated digital rig

Flex 6500 – Four Slice Receivers: Two running WSJT-X, one running MMSSTV, and the fourth running EasyPal. Add a Comet CHA-250BX Vertical @ 10ft and that’s it!

Barefoot Digital: 100 Watts into a Vertical

I wanted this to be a simple barefoot operation with a dedicated radio and antenna. I’m using a Dell 7050 micro PC and have the Flex displays “cranked down” in order to limit CPU usage to a range of 40-60%. Works great!

Evenings here have become a lot more interesting!

The past few evenings on 30 and 40 meters…See what I mean?

Every day this new digital mode attracts more and more people to the airwaves. It works with the briefest of openings and the software needed is free to download. It takes up about 60Hz only and works great with weak signals.

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TelePost LP-100A: Digital Vector RF Wattmeter for the Flex 6500

TelePost LP-100A the Perfect Choice

TelePost LP-100A
An opportunity arose for a great deal on an LP-100A. I went !BANG!

I came across an 8 month old TelePost LP-100A up for sale on and quickly pulled the trigger. I’ve owned LP-100’s before and have always enjoyed having one. After the purchase of the LP-500, I got to thinking about a dedicated wattmeter for the Flex 6500.

LP-100A: World Class Hardware

Everything you need for critical station monitoring, tuning and protection on one screen. No other meter has dual bargraphs, OR a graphic display with solid bargraphs, OR bargraph with 90 bars for fine tuning of Power and SWR, OR an SWR alarm with snooze mode, OR a “sticky” bar for graphic peak hold indication… let alone having them all on one screen! This is by far the best display for tuning a manual tuner, without having to change display mode for normal operation. It is also the only meter with 11 bands of frequency indexed NIST traceable calibration points using a built-in frequency counter.

Plus, the TelePost LP-100A has additional modes no other wattmeter has when you desire them... vector impedance, dBm/RL, calibrated field strength and compression ratio.

Metering for the Flex Digital Station

It’s a good idea to have a decent wattmeter monitoring SWR when you’re running full duty-cycle modes like FT8 and SSTV. There are lots of good reasons to have one! Right?

What Does It Say?

The LP-100A indicates 88.4 watts at 1.56:1 SWR on 7.074 mhz FT8

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