Flex 6800/6800M

Paul Christensen, W9AC

Given FRS' ability to rapidly design and produce new hardware product, I have to believe that by next year's Visalia or Dayton Hamvention, we'll start hearing more about a successor to the 6700. So, if my prediction is anywhere near correct, it may be helpful to FRS and its customers to have some idea as to what we want in a new flagship transceiver. 

I also think it's more productive for the user-base to present these ideas than for FRS to reach out with questions which would undoubtedly create even more insanity among the current user-base than what we've recently witnessed in the current 6400/6600 discussions. 

That said, here's what I would like to see in a 6800/6800M transceiver:

1) Tracking preselector.  Build upon the new contest-grade 7th-order BPF used in the 6600 and make it even more versatile by incorporating an automatically tracking preselector that mimics the excellent HEROS Cat design.  Presently, I use the HEROS unit with DDUtil and an ANAN 200D (but yes, I do own a 6700).  The HEROS unit tracks frequency through DDUtil and sets up an optimized BPF for every frequency of operation as tuning frequency changes.  Secondly, the HEROS creates notch filters on opposite HF bands for even more alternate band rejection. Of course, rather than use DDUtil, SSDR would manage all the tracking -- and allow the user to have complete control over BPF and notching functions.  It's the ultimate in front-end filtering.

2) Include a dedicated adaptive pre-distortion RF sample input. 

3) Allow for complete PA stage bypass.  The future with external amplification is with high-gain LDMOS (and equivalent) technology.  The newest LDMOS amps allow for 1-2 watts input to develop 1.5KW+ output power. When using these amps, a 100W PA is wholly redundant and extraneous to the RF amplification process.  While we here in the U.S. eagerly await a change to the FCC's 15 dB rule, many countries in the rest of the world do not have this egregious limitation. 

4) We need manufacturers to take a stand with the APP power connector.  I am not going to enter into a debate about the use of these devices on transceivers, but I would be surprised if any military/DoD operation would accept this connector in their specifications.  To the ARES/EMCOM crowd, pigtail adapters work fine.  I would like to see a return to the AMP Mate-'n-Lock or Molex style connector.  In the alternative, the APP should be recessed onto the PC board.  The chassis would have an integrated rectangular channel to eliminate all up/down and lateral movement.  Finally, a plastic or steel spring would be used to flip up/down on the back of the APP as a retention device.  This prevents accidental pulls. There's nothing that prevents using both the APP and Mate-'n-Lock together, in parallel on the rear panel.  Then, pick the connector of your choice.

5) Keep the power, mic, CW key and phone connectors on the front panel.  I realize the trend is to minimize manufacturing cost by placing as much as possible in a "no-wires" design on a PC board.  For those paying-up for a flagship transceiver, I think it's safe to say most owner's would pay extra to keep this convenience.

6) For the 6800 (non M version) please keep the small form factor (SFF) of the present 6700.  To keep manufacturing costs low in the new 6400/6600 series, FRS likely decided to keep a one box-size frame for all four models.  The extra size was needed to accommodate a Maestro-like panel, but that extra vertical space isn't needed in non-M versions.  Have a look at most ham shacks today, and we've got dozens of devices unlike the days when we may have only had a few pieces of gear. In my case, three 22-inch monitors alone consume a lot of upper desk space.  Rack mounting?  Sure, but I've already maxed out a lot of rack space.  Let's try and minimize the "RU" size when possible.

7) Faster boot time.  This probably goes with SSDR progress.  Current boot-time is painfully long and should compete with the likes of the IC-7300, ANAN 100/200 and SunSDR2-Pro -- all of which boot in under 5 seconds;

8) Cleaner switch-mode DC-DC converters and better EMC shielding. I admit, I sometimes obsess over stuff that doesn't affect normal operation.  But it unnerves me to see broad, switch-mode spikes meandering at the -130 dBM and some at -120 dBm level, even when they're spaced far apart with no antenna connected.  Let's try and do a better job with EMC at these low signal levels.  I do know it's hard when were dealing with such minuscule signals levels, but some other manufacturers' hardware does a better job in this area.    

9) Please keep PIN diode T/R switching!  I would hate to see a return to "K logic" as a cost cutting measure.       

Those are my ideas for future improvement in a new flagship transceiver.  What ideas do you have?

Paul, W9AC  




      

Tim - W4TME

One comment.

#3 we do that now for all radios.  Just select the XVTR port for transmitting.

Paul Christensen, W9AC

Tim, I thought that XVTR power was lower than 2 watts.  No?  I guess I need a re-read of the manual!

Paul, W9AC  

Tim - W4TME

It is.  But several existing LDPAs are using 10 dBm.  Just a data point in your discussion.

Steve (N9SKM)

6) They stated part of the form factor change was also to allow modular construction on boards instead of 1 main board for ease of repair.

Norm - W7CK

I would really like to see VHF/UHF added with full duplex capability.  Since the 6600 is modular design, maybe have the ability to add a separate VHF/UHF board.   VHF/100w and UHF/50w would be great as to not require an outboard amplifier.  I'm trying to reduce the mess of wires and boxes in my shack.

KC9EI - Dave

Now that's the way to make useful, constructive suggestions.!

Ria

In the future a LDMOS amp with a simple driver stage should be all that is needed. No need to waste space and power consumption with a 100 watt PA. Beko already has these and homebrewers are building them.

Rob N4GA

This is cool. I build LDMOS amps and use a 16dB atten on the front end. What's the power out of the XVTR port?

Rob, n4ga

Ria

Up to +15dBm on HF-6, +7dBm on 2 meters. 

Paul Christensen, W9AC

15 dBm is approximately 30 mW.  That's not enough to drive current LDMOS amps into their fully-rated power capacity, even with no attenuator inserted between the exciter and LDMOS PA input.   Ideally, we would want an adjustment range up to about 2 watts with currently available device gain.

Paul, W9AC 

Rob N4GA

Correct. I just didn't know if 15dBm was the max. 

Larry - WA7LZO

Hopefully, if FCC approves the removal of the old CB driven reg which currently continues to restrict the maximum Beta of Ham PA's to 15 dB, then Ham TX's can be designed like many high powered commercial and military HF transmitters. They typically use exciters to drive their big PA's, with output powers of their transceivers ranging from 20 to 75 mW.

Companies like RCI and Harris offer HF transceivers with a self contained 100 watt PA, but for customers needing to run 1 kW, and higher, they configure these systems by eliminating the 100 watt PA deck is such models. Such transceivers drive a big PA chain of amps.They stack up whatever number of "blocks" of 1 kW solid state bricks, providing power levels of 1 kW to 25 kW, and even much higher. Any single brick failure is barely noticed (6dB = 1 S-unit).

Using an exciter approach (20 to 75 mW) to drive a big PA will also help to produce a cleaner final signal. This way, the transceiver chassis can also physically shrink, let alone provide room for a small switcher to power the exciter and receiver, plus logic.

BTW, I believe the SPE Italy petition to the FCC late last year to remove the 15 dB restriction was set aside, for now, by FCC, but I think it remains alive for further consideration sometime down the road.

Br,
Larry
WA7LZO

Ria

Right, that's why I said a small driver stage had to be before the amp. 

Larry - WA7LZO

I believe SPE amps sold in Italy are configured to "want" only 20 to 60 mW of input drive power, right off the proverbial "shelf!" Let's hope the FCC dumps this antiquated anti CB reg, and pronto, so we Hams can start enjoying the benefits! 

Ria

Not true. 8-12 watts drive for full output. At least mine only needed that much. 

Ria

I believe the SPE Italy petition to the FCC late last year to remove the 15 dB restriction was set aside, for now, by FCC, but I think it remains alive for further consideration sometime down the road.

This was Bob Hardie, who owns the US dealer (Expert Linears America). He requested first that the 15dB rule be eliminated and that he get an exemption in the meantime for his company. Flex opposed the exemption but not rescinding the rule. The FCC agreed and denied the request. The petition to remove the 15dB rule completely for all remains.

Steve K9ZW

An additional consideration for Point 4) on Power connectors - Consider the Cliffcon power connectors.  In this class the Hilberling PT-8000A already uses them, and connectors of this grade are so much more robust and resistant to accidental pullout. 

Added item 10) Upgrade to N-Connectors on the radio (or offer N-Connectors as a factory installed option).

73

Steve K9ZW

Ria

I would definitely like to see N connectors as an option. I hate PL259s and use as few of them as possible.  

Clay N9IO

Paul,  #4 I totally agree on that point!!!  Yah I know, no discussion it's just fact...

That practice should have never happened.

Ken - NM9P

Good suggestions:

I agree on beefing up the power connectors.

I would even agree on N Connectors.  Even at HF, they are more secure and more impedance constant.  Albeit they are more expensive on both the rig and coax end.

Not sure I agree about the form factor... As much as I like the thinner cabinet of the 6500/6700...if the new box is better for the electronics and design engineering, keep it.  Don't sacrifice performance and maintainability for case size preferences.

The same for rear panel mic, headphone, & keyer jacks.  Right-angle adapter cords are relatively inexpensive and can be brought out under the rig.  Let them wear out instead of the expensive ones in the rig itself.

Additional suggestions for a possible 6800/M:

11) In addition to the 2 Meter output, incorporate two, or even more, independent XVTR ports that can be assigned to different SCU's, allowing for easy full-duplex VHF/UHF or satellite operation.

12) build in more than one Mic connector.  I can see switching back and forth between studio and headset mics eventually wearing out a single connector.

13) if possible and not too expensive, I would prefer to see 1/4 inch jacks instead of 1/8 inch (3.5 mm) jacks on the flagship rig.  If the Mic is a true balanced input, a 1/4 inch would be acceptable instead of an XLR-1/4 inch combo.  Even though the Combo XLR is very nice, a 1/4 TRS is just as good and easier to wire.

14) incorporate an additional button or two on the 'M' version that would function as a "select Active Slice" button, and perhaps an additional one as a "Select TX Slice" button that would allow stepping through the up to 8 different slices.  Allow additional pans/slices to be displayed on the HDMI screen.  If the HDMI screen is not active, then the buttons could shift "pages" on the main screen to access additional pairs of pans/slices.   

I might have others later, be these showed up first...

Ken - NM9P

Steve K9ZW

I'd skip an "M" model, but would like a small display showing health, menus, diagnostics and configuration settings. 

If an "M" model is a must, I would separate it from the main unit with a tether, rather than wled it to the front of the unit.

73

Steve K9ZW

KF4HR

My wish is for one black box that does HF, VHF, UHF, fully duplex satellite operations, digital modes, multiple transverter ports, 8-slices, performs as an excellent EME base platform, and top-end receiver performance.  I'd stand in line for such a box.

Steve Gw0gei

At least three tvtr outputs please with up to 10w drive on 4m 2m and 70cms Split tx on hf and vhf i.e. Ability to split hf drive to two antenna sockets 1 and 2 to drive two amps and two antennas in different directions and with separate split audio from ant 1 and 2 with ability within ssdr to split the audio left right etc Ditto on 6m and above - ability to split power out to two or three antenna sockets with separate rx from the different antennas so simultaneous tx in three different directions and ability to put both ears on all, two or just one rx line

David Orman

Agreed! PL259 is the bane of my radio existence.

Steve WS5W

me too! I have a credit card ready:)

Tom

Clean TX signal-PA with high voltage transistors, Attention to clean signal even without pre-distortion.

Tom, SP7WT

Wayne Westfield

Here's hoping (scratch that Hope is only unfound disappointment) Here's wishing the 6800 comes out soon, I am putting of the upgrade from 6500 to 6600 for this bigger and badder piece of hardwarer.

Bill -VA3WTB

Tell us,,what does the 6800 have in it,,tell us more about it...

Wayne Westfield

well its vaporware now, that is what this thread is about a conceptual 6800

Ryan - NC4RA

Please keep two mic inputs and add N-connectors