Flex 1500 and CQP

Here’s the bottom line…the FlexRadio 1500 is pretty close to being a contest-quality rig.

At 5 watts you get what you expect and a lot of what you might not expect.

I upgraded a cheap E-Machine 2 gig PC with Windows 7 (HIGHLY RECOMMENDED) and loaded the FlexRadio SDR software and everything was up and running with the sole exception of CW from an external key or paddles.

Seems the 1500 uses a hardware interrupt when a key or paddles are plugged in while the excellent internal CW keyboard and memory bank uses software which is unaffected. Some folks are claiming that a quad-core PC with 8 gigs of RAM overcomes this issue but so far, no joy here. A computer with this capacity is going to cost $600 or more but then again I need a computer for the logging program and other stuff.

It’s a little disappointing that FlexRadio would sell a radio they knew had a hardware defect but this has the feel of an engineering decision verses a marketing decision. If I’m guessing right the engineer would say “look we can fix this later but right now we’ve got guys clamouring at the door with money in hand so let’s relieve the pressure we’re feeling by selling the radio right now.”

This doesn’t fill me with confidence about buying a second (maybe a Flex 3000 with 100 watts PA and autotuner which would have been handy in the 1500. More about that later.) radio from FlexRadio.

A marketing guy would sooner shoot himself than sell a defective product. Why? Well it’s like selling a brand-new car with a crack in every windshield. Sure you know the windshield will be fixed later but everybody who buys the car has to explain that it’s a great car but yes the windshield is cracked but the company promises to fix it.

So let’s get back to the contest. I fired up the software and the Flex worked perfectly (with the CW exception … see what I mean) and I had only one moment when the audio went off a bit (likely an issue with the sound card in the computer) and a quick restart of the software (which takes 10 seconds) fixed whatever went wrong. Don’t think the Flex was the issue. Whenever I restarted the system, it worked perfectly.

I started by working guys on 20 meters on Saturday. If I was in the clear, the other station would work me easily. I even broke a couple of small pileups but I think that was more operator skill πŸ™‚ than power. Big strong signals off frequency were no issue whatsoever πŸ™‚

The receiver as far as sensitivity and selectivity is better than my IC-756 (which is pretty good IMHO) but the front-end isn’t as robust in the face of egregious or unwelcome local interference from a guy running 100 watts 360 meters north of me on the same band.

It’s not impossible but when Harry VA3EC fires up I need to get a couple of hundred kilohertz away from him. On the IC-756 I only need to be 10 kilohertz to work around him. I guess this is only fair as when I had the SB-220 amplifier I wiped Harry out. He was not happy.

The 1500 has one level of attenuation and three levels of preampfification. Adding preampfification did not cause any noticeable issues as far as introducing interference or birdies is concerned. Can’t say the same about most of the big box radios I’ve used in contests.

I was getting a few guys saying the transmit audio was pretty harsh but I couldn’t tell using the built-in Flex 1500 monitor function (which has a latency delay due to my old computer and is pretty much unusable as the delay will drive you nuts. A quad-core computer might solve this issue.) although the meter on transmit was reading over 100 per cent (which should have been a clue).

Harry helped me set the audio down to where I had sufficient audio to drive the rig to full output. The meter on transmit now read 80 to 110 per cent and I could work guys who I could barely hear on 15 meters (which had zero noise on Sunday afternoon making for some amazing contacts when W6’s were fading in and out of the noise level but who would get my report. Cool.)

Overall I had very few requests for repeats (no more than I’d have running a 100 watts) and occasionally I’d get S-8 report or better on occasion. I couldn’t run at 5 watts. That was an effort in frustration as (a) it felt like nobody could hear me and (b) I couldn’t hold a frequency.

The Heil headset (a two-pad Traveller with a HC-5 element) worked fine but whoever designed the two-foot attachment cord obviously never wore a headset during a long contest. The short cable from the headset is nice and light and has a push-to-talk switch with a clip on the back so you can attach it to yourself so you can find it quickly. (You have to be able to lift your hand from the computer keyboard to make a call ). The attachment cable has a large, heavy connector and thick heavy cable to the mic plug. The entire cable assembly should be much lighter with a less industrial strength connector. As it is, it’s clunky.

And speaking of the push-to-talk switch, this rig cries out for VOX but none is provided. I wonder if it would be possible to create a VOX function in software. I also need to check out the I/O FireWire plug on the back and maybe I can wire in a foot switch. Not the best solution but I’ve run 48-hour contests using one and it works.

What else? Well it sure is strange to run a contest station that doesn’t have a BIG box sitting on the desktop. Seems weird. Same for the tuning of the rig. I miss a tuning knob (A Griffen knob is on back order from Flex since May!!) but you get used to using the mouse.

Also the rig runs only slightly warm and is powered by a five-amp dedicated supply. Since there are no controls on the box, it can go anywhere.

Another issue: Flex decided not to include an SWR meter because they said it wasn’t needed as the rig didn’t have a tuner built in. Geez who thought this through?

The 1500 sure could use a meter as any SWR or other issue that causes less than the full 5 watts to reach the antenna is a BIG issue in a QRP rig. If you’re running a 100-watt rig and you’re only getting let’s say 50 watts to the antenna, you might not even notice. With the Flex 1500 is you’re down to 2 or 3 watts it makes a difference between being heard and not heard.

Okay so much for the gripes, what is good about the 1500.

Just about everything else πŸ™‚

The audio is lovely to listen to. With a quiet band I could back off the AGC-T (it’s sort of RF gain) control and have noiseless communications where stations popped out of nowhere with perfect audio. Really cool. The rig will drive self-powered computer speakers if you want to sit back and monitor the band.

There are a ton of ways of changing frequency including sliding the panoramic display with the mouse or using the mouse wheel (the range can be varied) or direct change to the frequency readout. Very nice even without the tuning knob 😦 BTW the built-in panoramic display is fabulous. Doesn’t the K-3 panoramic display cost about the same as the entire 1500? Humm.

I’ll skip repeating the list of features but for contesting two VFOs (nice), selectable and infinitely adjustable filtering which is pretty much brick wall solid (with the above mentioned exception of close-in interference). This list goes on….160 meters to 6, all mode and will connect to third party software like your logging program or RTTY engine via a virtual audio cable (VAC) which is my next step. There are a ton of individual controls which aren’t overwhelming but seem pretty thorough.

So now what?

I could buy a 50-watt amp and an auto-tuner and I’d be off and running but when we look at the cost that becomes problematic.

The rig is $600. The 50-watt amp is at least $500. An autotuner is $200 and a Flex 3000 is $1500. Humm. The 1500 makes for a great QRP rig as it sits. I’d like to get my hands on a Flexradio 3000 before I made a final decision.

So the question becomes a Flex 3000 ($1500) or an IC-7600 ($4,000) or a K-3 ($2,000 and rising to $4,500 when all is said and done plus a medium-size amp like a Tokyo Hy-Power HL-1.5 ($2500) or an Acom 1011 ($2200).

Decisions, decisions. I need more time with the rig in actual contest conditions.

So I’m still not sure I prefer the software defined radio approach over the big black box but I overall I had a great experience on the California QSO Party and did way better than I had anticipated (200+ QSOs). Time will tell as will how well the 1500 interfaces with Writelog and some of the other great software out there.

Would I recommend the Flex 1500?

It makes for a GREAT QRP rig (especially once the CW is fixed) and you don’t need an autotuner (I’m using the cheapest smallest MFJ manual tuner and a QRP-capable watt meter which works fine). Would I buy a another one is this one failed? Probably not. I’d buy the 3000 with the 100-watt PA and autotuner although that kind of defeats the idea of QRP doesn’t it. (And don’t tell me I can tune it down to 5 watts. I can do that with the 756 and never have.)

Pretty neat little rig and contest-capable with the noted issues.


3 thoughts on “Flex 1500 and CQP

  1. I heard one of the “6” stations working you on 20m . I was running 5w with my FT817 with a W3EDP antenna at about 20 feet agl aimed east west.

    He called QRZ and we both tried it seems… He got you first (were you using a beam?) and I got him right after…

    It sounds interesting for a QRP rig… Perhaps ….


  2. Peter,
    your here below statement sound quite stange as the measurements I have taken shows a dinamic range far superior to the IC-756, thus the 1500 front end should be actually much more robust???

    Anyway thanks for your comments, apart from the exception I mentioned, I very much agree with everything else…including the CW issue
    73 Clay, I4LEC

    It’s not impossible but when Harry VA3EC fires up I need to get a couple of hundred kilohertz away from him. On the IC-756 I only need to be 10 kilohertz to work around him. I guess this is only fair as when I had the SB-220 amplifier I wiped Harry out. He was not happy.

    40m band IP3 Measurements.
    Band Ref = MDS
    Freq. MDS IP3 DR
    MHz Pre-Amp. dBm dBm dB
    7,050 -10 -107 37 96
    7,050 0 -115 31 97
    7,050 +10 -126 16 95
    7,050 +20 -133 12 96
    7,050 +30 -135

  3. Pingback: QRP- Doing more with less « VA3QV’s Weblog

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