Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

best amp for auto band switching

Hello , I am wondering if I would be better served by buying a solid state auto band switching amp to go along with the extreme versatility of my Flex 6700 rather than my tube amp . Is this a good idea ? If so which works smoothest with the flex ? Thanks for your help . John Molenda kb2huk

Completed · Last Updated



  • Kirk, K6KARKirk, K6KAR Member
    edited June 11
    John, I use the Prometheus DX2400L and love it. It is auto band switching and is the only SS amp that is (key down) capable at legal limit. http://www.dishtronix.com/prometheus.html I use this with both my 5000 as well as the 6700. Kirk, K6KAR
  • Al_NN4ZZAl_NN4ZZ Loganville GAMember ✭✭✭
    edited March 2017
    John, Auto band switching is available on both tube and solid state amplifiers and both are being used successfully. Like Kirk / K6KAR I'm also using a Prometheus DX2400 and it works great. I have some diagrams and pictures of the interface I'm using on my web page. http://www.nn4zz.com/Prometheus.htm Regards, Al / NN4ZZ
  • K6OZYK6OZY Member
    edited February 2017
    I'm using an Elecraft KPA500 & KAT500 with my Flex 6700 with great success.
  • Sergey R5AUSergey R5AU Sergey Member ✭✭
    edited April 2017
    I am using 2k-fa in combination with DDutil with success
  • W5UN_DaveW5UN_Dave Member ✭✭
    edited February 2019
    I also use the Expert 2K-FA amp with DDutil to limit max drive power. This works wonderfully for me.
  • Rich K3SOMRich K3SOM Member ✭✭
    edited December 2013
    I have been using the SPE Expert 1K-FA since 2008 - first with the Flex-5000 and now with the Flex-6700 through the DDUtil interface. This solid-state amplifier has worked flawlessly from 160 through 6 meters and from ragchewing to contesting activities.
  • Ron - K1RERon - K1RE Member
    edited August 2016
    I'm using an Alpha 9500 with the Flex 6700. Also have used an Icom IC-PW1 (not auto bandswitching) as a backup, but needed to add 100 ms transmit delay to keep amp from faulting. I'm not using any ALC but wonder if others are. 73, Ron, K1RE
  • GregGreg Member ✭✭
    edited October 2016
    I use a yaesu Quadra that is controlled by a Microham Stationmaster. The Stationmaster is connected through DDUtil. It handles amp signals as well as automatic antenna control and the ability to select multiple antennas based on user defined band segments instead of just by band. 73 Greg AB7R
  • Al_NN4ZZAl_NN4ZZ Loganville GAMember ✭✭✭
    edited March 2017
    Ron, ALC is not supported yet. Although it is not listed on the roadmap, it is planned for V1.1 in January. http://community.flexradio.com/flexradio/topics/rf_power_alc Regards, Al / NN4ZZ
  • Ron - K1RERon - K1RE Member
    edited August 2016
    Thanks Al. I wondered since the ALC setup is described in the support manuals. Regards, Ron, K1RE
  • Rich K3SOMRich K3SOM Member ✭✭
    edited January 2018
    The Expert 1K-2A includes auto band switching, built in auto tuner with programmable auto-tracking sub-bands, built in power supply, two transceiver inputs with built-in frequency counters (if CAT is not enabled) and four antenna output connectors. The Italian design also included a very stylish carrying bag for those weekend DXpeditons to far off places. Right now I run it without ALC on the Flex-6700 (not yet supported) without any problems. John, you have many quality choices available that will work quite well with these 6000-series transceivers.
  • Bill-W9OLBill-W9OL Member
    edited October 2016
    Also use a quadra here but use DDU3 to automagically control the band & ant choice using the 'Other' option of the Ports-Parallel Port feature. Just like having a KW tranceiver, always connected to the correct antenna.
  • John MolendaJohn Molenda Member
    edited March 2014
    Thanks for all your input . I have decided to try the lesser expensive ameritron als 1300 . The band switching sensor software has yet to be worked out by ameritron but hopefully it will . Thanks for all the info on all those great amplifiers . john kb2huk
  • edited July 2018
    Using the Acomm 2000a with my 6500. Works wonderfully. I'm sure the alpha 87 and 9500 would do the same.
  • WA6FXT MikeWA6FXT Mike Member
    edited June 2017
    My Tokyo Hy-Power is great. Now, if only the Flex6700 could control it... No local computer, when running remote, so no DDUTIL. Soon, I'm told. Mike
  • Rich K3SOMRich K3SOM Member ✭✭
    edited January 2014
    John, Hope should not enter into a purchase decision. A wise person told me". . .you soon forget what you paid for it, but the quality is never forgotten!" Many quality amplifiers have been described here by both me and by others. Please let us know what you finally purchased! Rich
  • k0eook0eoo Member ✭✭
    edited March 2017
    And last but not least, I'm using an Alpha 87A with DDUtil and my 6500 and they have been working flawlessly....
  • Larry BenoitLarry Benoit Member ✭✭
    edited November 2018
    John, Ameritron ALS1300 band switching can be controlled with DDUtil and the Ameritron ARI-500 interface connected to your computer with a parallel interface. For details see this wiki... http://w5jgv.com/ALS-1300_to_F5K/ Note that the wiki shows a modification to an older model ARI500, which is not necessary because the device was redesigned. 73 Larry KB1VFU
  • Ed bakerEd baker Member
    edited September 2016
    Tube amplifiers are still the best bet for the buck. But changes are in the works that will give you better IMD both in Solid state units and Tube units. The question leaves us presently with what one are you using . For Me OM power amplifiers are great. .The entire line exceed the FCC emission regulations . Yes It follows my 6500 Yes it has remote Ethernet control Yes Cheep re tube . The real question is , Now we have the best radio out there (As Of 1/20/2014 ) OK flex it's up to you !!!will you keep it that way.
  • K4VAE / VerneK4VAE / Verne Member
    edited January 2014
    Rich, I just purchased a 1K-2A for my 6700. Any chance we could get together offline to discuss your interfacing? I have seen several different posts regarding interfacing the 6700 and amp and would like to better understand how you have made it work. Thanks! Verne / K4VAE [email protected]
  • W5UN_DaveW5UN_Dave Member ✭✭
    edited February 2019
    My 2K-FA works very well with my 6700. I do full breakin at 30 wpm and full power, no problem.
  • Joe - KC2TNJoe - KC2TN Member ✭✭
    edited November 2016
    Dave, could you provide details of the DDutil-2K interface to the Flex. I currently have a F5K but plan on upgrading to the 6500. My 2K should be here in a few weeks. Joe - KC2TN at Comcast.net
  • skysky Member ✭✭
    edited June 2018
    I use a vintage Heath Chippewa KW amp that is fully manual. It requires human intervention to operate and select the desired band (me!).  It is over 60 years old, runs beautiful mercury vapor voltage rectifiers and has never failed to work 100%.   We will see how many solid state computer amps are running in the year 2050.  Hi hi!

  • Walt - KZ1FWalt - KZ1F Member
    edited November 2016
    I second the Elecraft linear and tuner solution. I've got both and they work great at a fraction of the cost of a Prometheus of Expert Amp. What multiple people told me when doing my research, anything beyond 600 watts is into the area of diminishing returns.
  • KY6LA_HowardKY6LA_Howard La Jolla, CA. Paris and Sablet FranceMember ✭✭✭
    edited June 23
    600W is far too small an Amp for serious contesting or serious DXing

    Plus it does not have sufficient head room to run high duty cycle modes like RTTY. I run an Expert 2K-FA. Totally automatic and idiot proof. It will run key down 2300W+ into a dummy load which is more than sufficient headroom to operate 100% duty cycle modes such as RTTY in contests. We had a couple of the tiny Elecraft 600W at the NX6T Contest Station but they were not sufficient for serious contest work ...great for portable Field Day but far too small.
  • K6OZYK6OZY Member
    edited September 2015
    Good thing I'm not a contest guy and like efficient non-rtty modes! 600 watts does me just fine and can run off 110v.
  • Ross - K9COXRoss - K9COX Member ✭✭
    edited September 2015
    Far too small is a rather harsh term, I would rather say about 1/2 an S unit. You don't suppose that some contesters run more than the legal limit do you? I don't understand why RITY is even used anymore, it is such an inefficient legacy digital mode with low spectral efficiency. If 3 dB is so important then there are numerous ways to get a much better S/N ratio for contesting. Is AM still a contest mode? (My comments are for the sake of sarcasm)
  • Burt FisherBurt Fisher Member ✭✭
    edited August 2016
    How about JT-65 for a contest, it would drive contesters crazy
  • David Decoons, wo2xDavid Decoons, wo2x Member ✭✭✭
    edited May 2016

    +1 on the Acom 2000A. Excellent amp and works flawlessly with the Flex 6000 series and DDUtil.

    Fed into a modified PalStar AT-Auto tuner that bypasses and selects the Yagi for 10, 12,15,17,20 and selects dipole for 40/80 with tuner in circuit.

    Truly point and click.

    Dave wo2x

  • Ken - NM9PKen - NM9P Member ✭✭
    edited December 2016
    Ha!  That's funny, Burt......But JT-9 Fast mode might be spectrum efficient and almost fast enough for a leisurely contest.  Limit it to 50 Watts output for all stations and you might have something there.

    But then again, I don't have enough quite enough patience to run JT-65 or JT-9 even for regular operations, except for MS and weak signal experiments.  But to each there own!  I am glad some folks are experimenting with those modes.

    RE: AMPS....The ACOM-1010 isn't auto-tuning, but anyone have a recommendation on it for moderate DXing and mid-level contesting?  It looks interesting to me, especially it's wide tuning range that may not require an antenna tuner for under 3:1 SWR.

    Ken - NM9P

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.