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630m / 2200m using FLEX

Doug - W5WTX
Doug - W5WTX Member ✭✭
edited June 2020 in Amateur Radio Interests
Is anyone on 630m or 2200m using a FLEX?  Just wondering what equipment folks are using for transmitters and pros and cons of using a transverter for receiving vs using the FLEX's 630m and 2200m capabilities directly.


  • Ken - NM9P
    Ken - NM9P Member ✭✭
    edited June 2020
    I have done some receiving on 630 Meters with my 160 Meter inverted L with good results. But I don’t have any way to Transmit. There are some ops using a high gain amplifier driven by the XVTR port to transmit.
  • Andrew VK5CV
    Andrew VK5CV Member ✭✭
    edited August 2018

    I use my F1500 on transverter and RX ports with a 1mW to 25W HF amp from an old commercial radio that splits the inputs. The 1500 needs outboard filters on TX and RX and so does the amplifier.
    The antenna is an inverted L for 160M with a 600uH variometer and 2:1 autotransformer. 50ohm to 25ohm.
    The 6500 is much cleaner on TX and RX. I am working on matching it to an HF amp for 200+ W.
    The Signature series radios are great on RX for 2200 and 630M with the Pixel loop.

    Andrew VK5CV.

  • Albert PA0A
    Albert PA0A Member ✭✭
    edited November 2018

    Hello Doug

    I am using my F6500 for RX and TX on both bands with good results. A small broadband amplifier at the transverter output (50mW) driving two separate power amplifiers one for each band. The power amplifiers are modified ex DECCA system FET PA’s designed for 1kW out. My best DX using WSPR on 630m is 9511 km (PA to FR5ZX)

    This is IMO the best way to go, RX needs no additional filtering unless you live next to a medium wave transmitter and for TX you only have to amplify the 10mW of the transverter output to a suitable level. Additional mixers and oscillators can only decrease the performance.

    73, Albert  
  • Lucas - W6AER
    Lucas - W6AER Member ✭✭
    edited November 2018
    I am looking to do something similar with my 6600M. I am receiving great on 630m using a 160M vertical (K6MM Design) and in the process of building a variometer for it to match it (hopefully) for future transmit. The amps I have found all have a slightly higher input need then what is coming out of the flex. Curious to see what others have done to get on the air. Once I select an amp and fine tune everything I will share it here.
  • Lucas - W6AER
    Lucas - W6AER Member ✭✭
    edited November 2018
    Doug, Which broadband amplifier did you use? I would love to bring the initial output up to 0.1 to 1W range to drive an amp. Thanks for any info!
  • Andrew VK5CV
    Andrew VK5CV Member ✭✭
    edited November 2018

    This one works well to 5w with an MRF660 I had.
    For MW it may benefit from higher value coupling caps.
    At MW a less exotic transistor may be fine ie BD139.
    Andrew VK5CV
  • WQ2H - Jim Poulette
    edited March 2020
    I think I've mostly settled on the TVTR2 for 2200m down conversion for the 6600M on both Rx/Tx. Presently in the process of building a 20-tap 3500uH coil / variometer set for use with an existing 160m multi-wave horizontal loop. The loop is well insulated from trees and structures, and I walk it at least once a week. It's a 'grand' experiment, but I'm having so much fun I can barely stand it. I also have another 80m 2-wave loop, and a 500m long wire (quasi-sloper), that I may also try.

    I intend to break the loop at the feedpoint, move the far end safely out of harms way, then connect the opposite feedpoint end to the loading set. I've got a pretty decent existing ground farm which is where I hope to position new feedpoint. Using a WaveNode with one of the new L/M-1 'thruline sensors' I should be able to dial it in pretty close. I'm rarely as smart as I think I am, but we clearly shall see ! Fun stuff.

    Jim, WQ2H
  • Lucas - W6AER
    Lucas - W6AER Member ✭✭
    edited November 2018
    I was considering that unit as well and still might go for it. Looks REALLY nice! Although ideally I was hoping to receive as I have been and pumping up the output from the transverter port. I will likely be a double jump to take the +10dBm (10mW) to about maybe +27 or 1/2W so it can drive something a little more significant, such as a 20-300W amp I have been eyeing to compensate for the super compromised antenna systems we likely all have for the band. 

    Alternatively here is a very nice design for an amp: http://www.w1vd.com/137-500-KWTX.html someone just shared this link with me. Class D but you can get away with it due to modes used. And the research continues. I will chime in as I find more info or when I finally get on the air on the new bands. I suspect I will be amp building during the holidays! Thank for the info Jim!
  • Lucas - W6AER
    Lucas - W6AER Member ✭✭
    edited November 2018
    This is pretty much what I had in mind, thank you!
  • Robert Lonn
    Robert Lonn Member ✭✭
    edited February 2020
    This post is over a year old! Any new and exciting updates??? Has any 135/500 Khz amplifiers hit the market place to use with my 6600M. 
  • Stan VA7NF
    Stan VA7NF President Surrey Amateur Radio Communications Member ✭✭
    edited February 2020
    I'm not into those bands but check out modifying induction hub amps.  VLF variable power oscillators up to around 3KW driving a coil antenna.
  • W1XYZ
    W1XYZ Member ✭✭
    I bought an LDMOS 100 KHz to 3 MHz amp on ebay for about $175 that produces a pretty clean 60 Watts on 472 KHz with about a 3 dBm drive and built an outboard 630 M Wattmeter to keep an eye on it. The amp runs on 48V which is common for a lot of these new LDMOS high gain amps that you can get. It worked so well I just purchased a new 6400 to go with it for a remote 630M station out at my farm, where i have a lot of space for long antennas and already have a remote HF station using RemoteRig and a TS-2000.

    I've also just started using SmartSDR for the Mac which seems promising, but does not have wspr, just FT4 and FT8, and even those not on 630M. Anyone have an idea how I can fool the system so I can at least put FT8 on 630 using SmartSDR for Mac? I'd rather not have to run another buggy side app.

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