Flex 6500 Review

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  • Updated 8 months ago
  • (Edited)

                                                          The Flex Radio 6500


By Bill Buchanan VA3WTB


As some of you know I used to write about high end audio, that was many years ago and it was a time I enjoyed.

This time I am writing about ham radio gear, another great pass time I enjoy.

I was fortunate to take advantage of the Flex Radio, used radio deal they were running. I ordered a Flex 6500 with a Flexcontrol wheel and the GPSO.

You may be asking, why review a used radio that is not produced any longer? I have had the pleasure of owning a Flex 3000 for about 12 years running PSDR. Over those years I always wanted a Flex 6500 but it was not in the cards for me. Now that I have one, lets take a look at it.


Meet the Flex 6500.

A direct sampling transceiver


The radio came shipped in double boxes, one slides into the other with a snug fit. I removed the inner box and opened it. Inside your met with a well modeled styrafoam cutout in two halves. Inside the cutout is the radio tightly fitted into the cutout. The radio is wrapped in plastic sleeve with a sticky flap seal.

Baring a Mac truck running over the box, damage from shipping seems very un likely.


The radio came with my Flexcontrol in it’s own little box well packaged, a hand mic, software CD, and power cord with Power Pole connectors on one end. And the radio came with the V2 license, that was a big plus.

The Flexcontrol plugged into the USB port on my computer, the computer found it, I then set it up as I like,. In the SSDR setup you can select many options to have the AUX buttons function as you want to. I wish there were few more AUX buttons to use, that would allow more choices and control.

But over all the Flexcontrol works well as intended.


The mic that came with the radio is an FHM-1, I tried it and found I was not able to make it sound very good no matter what I did in the EQ. I all but gave up. I took the mic front grill off and used a drill to open up more holes in front of the element. I found from looking at it closely the front grill was mostly closed and it would not allow for my voice to make it through to the mic element.

After I opened up the front grill further with more holes the mic became a very good sounding mic.


The Power Poll connectors on the power cord was not a really good connection, if you plug it in and out to many times this may happen. I simply used a small flat screwdriver and forced the metal tabs inside back into place to make a better contact, It worked.


After unpacking I set the radio on my desk, I smiled, the quality of the build, fit and finish was outstanding, very soled.

On the front face is a Foster mic input, Phones, And a Key input. In the center is a small screen that can be dimmed. It is used for showing alarms and gives messages on what the alarms mean. Buy default the display reads Flex 6500, but it can be changed to your call sign in the setup menu in SSDR.

The display is also used for diagnostics with pressing the multi function button next to it using the arrows left and right will bring up information inside the radio. And it is used for the radio re set.


I think Flex Radio could have made better use of the screen by including more information that the user may want, such as Voltage, and Temp, and so on.


On the far right side of the front face is the power button. It is a soft push type. Above the button is a light that changes to several colours to show the state the radio is in, clever.

I had the GPSO installed at Flex Radio, nice option. It comes with a 15 foot cable and antenna. I have the antenna stuck to the inside window and it works great. After the radio is finished booting in my case the light above the power button blinks blue till the GPSO is locked on to the satilights and stays steady blue.


On the back of the radio is all the connections you would expect from such a sufisticated radio. I am not going to explain all the connections here, But there are a couple worth mentioning . On the back is a professional type XLR connector with an 1⁄4 inch plug in it’s center for balanced mic input. This is not found on many ham radios. It makes a solid connection to many professional mics, very nice.


Connecting the 6500 to everything needed was easy, the back connections are well laid out and easy to understand, all connections are made first rate, nothing spared. I wish they had put another phone plug in the back beside the mic input for plugging in the head phones rather than connecting to the front and to the back. I am using a Yamaha CM 500 headset. One plug is in the front phone plug and the other reaches around to the back to the mic input. I chose to connect the 6500 directly to the computer by way of the Lan connection. Or I could have connected through the home network using the router.


Time for the software install and setup, I followed the directions and the install was just to simple, there just has to be more to it then that? Keep in mind the 6500 is a thin client un like the Flex 3000 witch is a fat client meaning the thin client does all the processing in the radio and not in the outboard computer. This allows for the SSDR software to be light and the install is fast. This also allows for a slower computer if you don’t have the latest and fastest computer.


After installing the SSDR software I registered the radio to V2. When you start the software you see a screen that allows you log on by remote or just connect.

After the software is running I started setting the radio up as like it, basic things like mic levels, proc, power out level, things that we all do on a new rig.

The setup was easy, this is one of the wonderful things about SSDR, it’s powerful simplicity. No matter how complex things are, SSDR keeps things in check, user friendly.


But you better have a large screen, many of the adjustments on the screen are on the small side. Such as the record and play back buttons, you have to get the mouse pointer right on the spot to make them work.

Talking about that, I would have liked those buttons moved to the top bar beside the menus and larger, much like the size of the TX button. Also it would have been nice if there was another Mox button to engage that would link it to the play back button so when pressing the play, it would transmit in one press.


As the radio is simply software I have a few comments about that, but I will not go into deep detail, that would take much time. The first thing I noticed when the software popped up was the amazing detail of the screen, full HD, very clean and sharp. The water fall is I think the very best in the industry. So smooth and crisp. The most minute details are seen and this is adjustable with a gain control in the display menu. The menus are well thought out and easy to and use. Each slice has it’s own flag attached to the band pass stripe. I find myself using it for most my adjustments, some of the adjustments on the flag are repeated on the side panel. I don’t know why.

I would like the flag and pass band marker to remain on the screen while I scrolled up and down the band, perhaps staying in the center. If there are other slices up then only have the selected slice fixed and let the others move.

Other then finding some adjustments small and not so easy to use with a mouse, I found that the meter level indicators could be a brighter red. But over all I found the software very user friendly and easy to understand, very powerful software it is, it has to be in order to be so simple doing very complex things.


I understand the direction Flex went with the noise mitigation. Targeting types of noise in order to keep the receive as good as possible, I find the WNB to be very powerful with a certain type of noise as well as the NB, yes they do work well, but only under a certain condition.

It is for me, the NR and the ANF that can be re worked to eliminate more of the distortion when turned on. I found the NR to work ok, but distortion is to high on signals. The same can be said about the ANF.



After the software is set up I then saved the profiles to store all my settings, I found it confusing to fully understand how the profiles are set up, mostly the global one. Pressing the power button starts the radio, You can hear the fans rev up, they are not to loud but if they were any louder it can be distracting. The radio then goes through a boot time, the screen on the radio tells what it’s doing, in my case it ends with my call sign displayed as I chose in the setup.

I ran the radio for a few hours here and there and found on some occasions the radio failed to start.


I took the Flex 6500 to field day last summer and it stopped working after a few hours. I then put my Flex 3000 in place.

After the weekend I contacted Flex Radio about my problem, I talked to Dudley back and forth till he said to send it back for repair. He sent me a shipping label and I packed the 6500 up and sent it back.

I must tell you that the service was crazy amazing. About a week turn around. The person fixing my radio emailed me and told me what they found wrong and fixed it, then bench tested it and promptly sent it back to me.

Back on my desk and ready to fire up, I was exited. I simply loaded my profiles that I saved and my radio came to life with all my settings just the way I left it.

It has performed perfect since the repair.


After using the Flex Radio 6500 for a few months I find it very enjoyable to operate. As I mention there are things that can be shored up, but the really great things over shadow the weaker things found in the software..

The Flex 6500 is by any standards built very well inside and out.

Flex Radio does fully support all models of Flex radio’s and will repair them as long as possible, parts pending.

A used Flex is a safe way to buy, I would do it again.


I could have gone into more detail, but you know...


By Bill Buchanan
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Bill -VA3WTB

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Posted 8 months ago

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Photo of Bill -VA3WTB

Bill -VA3WTB

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From reading this over, looks like I need a proof reader..lol
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N0AZZ

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Bill I also bought a Pre-Owned 6500 from Flex and traded a 6300 in on it that I received in a trade, liked it so much had to have a 6500 and traded the 6300 in on it. Wanted a 6700 but a bit out of reach at the moment maybe later on it might happen.

I felt it was an exceptional deal + the trade, ver 2.x software included, plus a check by the techs and a warranty. No other radio mfg. does this not even close.

Like you I do worry about parts if needed on a discontinued radio but feel support and parts will be kept in stock and are available. They also have one of the very best and easy setups for the Digital modes of any radio on the market today. 
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Bill -VA3WTB

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N0AZZ, thanks for your comments, I think history will show the Flex 6500 will be the most loved radio in the lineup. It is feature rich, and it is in line still for further up grades.
It is in the middle between the 6300 and the 6700, so the price was and is just in the right range.