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External 6700 OTS filters

KF4HR
KF4HR Member ✭✭
edited April 2020 in FLEX-6000 Signature Series
In a recent K5KUB interview with Gerald (below), he mentions external off-the-shelf filtering can be connected to the Loop port connections of the 6700 to add the 6600 receive filter enhancements.  Can someone elaborate on what off-the-shelf filter this would be?  And its availability?

https://youtu.be/UGNVjGKdvbM?t=8677

Butch
KF4HR

Answers

  • Michael Aust
    Michael Aust Member ✭✭
    edited May 2017
    Have two of these filter's with my Flex6700 driven by Arduino board 

    Turn your Flex6700 into Higher Performance like the Flex6600M 

    Each Filter on each SCU of Flex6700 giving 70dB reject per SCU  band to Band reject features 

    Super Radio ! 

    Less than $200 - $250 ( 1 or 2 filters ) and put in nice Box with Flex6700 following along ! 
    73 Mike

    https://www.sv1afn.com/ham_band_presel.html

    imageimage


    My Band Decoder below driving the Filter Band Boards

    https://remoteqth.com/arduino-band-decoder.php

    image

    image

    image
    image
  • Michael Aust
    Michael Aust Member ✭✭
    edited April 2020
    Well, if you want a more turn key solution this is it
    https://herostechnology.co.uk/pages/SCR_Preselector.html

    73 Mike

  • Jason NR0X
    Jason NR0X Member
    edited May 2017
    I use a pair of Dunestar 600 filters with my 6700.  I interfaced it to the USB port on the back of the radio, using an 8 Channel USB Relay board from ebay.  I set it up as a bit cable in the usb settings.

    Jason NR0X
  • Sergey R5AU
    Sergey R5AU Sergey Member ✭✭
    edited May 2017
  • KF4HR
    KF4HR Member ✭✭
    edited November 2019
    This is interesting.  I wasn't aware 6700 owners were already using external OTS filters.  Can I assume these filters provide a noticeable difference under normal operating conditions?
  • Ria
    Ria Member ✭✭
    edited May 2017
    Any serious SO2R contest operator uses filters. Either you use a flter set, individual filters or stubs. I use 2x 5B4AGN filters. They keep both SCUs isolated so when I transmit on 80 I don't shut down the radio when listening on 40 in FDX mode. I switch them manually right now but I am getting BCD cables to switch them. 
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited May 2017
    image
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited May 2017
    these are automated.  all bands including warc
  • Michael Aust
    Michael Aust Member ✭✭
    edited May 2017

    One can easily transform Flex6700 into becoming a sort of roll your own Flex6600 Super Contest Radio type of radio with not much of an issue because of the Loop 1 and Loop 2 Ports Connectors on the back of the Flex6700 for each SCU to insert OTS HF Ham Band "Off the Shelf Filter's "

    Thing missing would be bypass mode of the OTS Filter if Passband BW went to wide, how to bypass OTF filter would need to be done somehow otherwise one would need a manual override on the external OTF's to possibly bypass it like in the Flex6600 series of radio's.

    Seems there are a few OTF filters out there, so that not the real big issue, so my Flex6700 can still be King of the Hill, Top of the Heap Type of Radio !

    Mike

    Flex6700 Owner : Love the 8 Pan's / Waterfall's, nothing like it !

    OTF = Off the Shelf Filter ( i.e. :from one from U.K. vendor in London or the SV1AFN or 5B4AGN OTF Filters boards/units out there !! )

  • K6HN
    K6HN Member ✭✭
    edited November 2019
    When using one set of filters is it best to put them in the TX path or RX path?


  • Ria
    Ria Member ✭✭
    edited May 2017
    I put mine between exciter and amp.

  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited May 2017
    right where they belong...  no need to over complicate things..
  • Ria
    Ria Member ✭✭
    edited May 2017
    I assume it's bypassed on WARC though. I don't have WARC filters and pretty sure we're running the same set. How are you controlling it? Bit or BCD?
  • Ria
    Ria Member ✭✭
    edited May 2017
    Oh I see you have two sets and using them just for individual bands. I have two sets, one for each SCU so I can do full SO2R on my 6700. 
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited May 2017
    yes there is another set of 2 obscured from view.
  • ctate243
    ctate243 Amateur radio contester Member ✭✭
    edited May 2017
    you can chain them together to cover both standard and warc bands.
  • KF4HR
    KF4HR Member ✭✭
    edited November 2018
    DX Engineering has an automatic bandpass filter in a nice enclosure (DXE-419) with over 40db of rejection, and Low Band Systems has individual band filters with 80db of rejection.

    Does anyone know if there's a video out there that shows the operational difference between 3rd and 7th order filtering during a contest?

    It would be interesting to know if FRS plans on coming out with an external band pass filter for the 6700, to match the receive capability of the 6600M. 
  • Tom
    Tom Member ✭✭
    edited December 2017
    Hello Sergey,
    Is there someone in Russia who manufactures this kind of filters?
    If I remember correctly, you provided some details in your earlier post, unfortunately I can not locate it. Quite an interesting idea!

    Tom, SP7WT
  • Tom
    Tom Member ✭✭
    edited December 2017
     Thanks for a prompt update, Sergey,
     Very interesting range  of options on the transmitter side!  Is there someone who manufacturers  receiving filters? I plan to improve RX side of my F 6700 first.

    Tom, SP7WT

  • Sergey R5AU
    Sergey R5AU Sergey Member ✭✭
    edited December 2017
    Tom, I wonna say actually you do not need any filters for 6700 except extremely sharp like crystal based . All others or will not give you visible advantage or will deactease IMD performance. Inband dynamic range of receiver of 6700 high enough and only thing you need in case real SO-X-R planning with you 6700. 6700 need only one thing - best antenna array! P.S. do not look RX only filters in Rus, but will do and give you update soonest .
  • Stan VA7NF
    Stan VA7NF President Surrey Amateur Radio Communications Member ✭✭
    edited December 2017
    Rx Filters can help when in "WIDE" mode, that is the internal front end filters are not engaged.  My example is an AM broadcast band filter so those stations do not mix in the front-end protection diodes.  Greatly improves VLF reception and SWL.
    Also for a front end protector if there is a chance of any strong local stations (like a KW 2nd op on another band)
  • Sergey R5AU
    Sergey R5AU Sergey Member ✭✭
    edited December 2017
    Stan , a first chapter of you message true for AM SWL reception on really long wires or out of band antennas , btw ATT must be engaged here, so for second part really good filters for HAM band must be involved as well in case any SOXR, were typically RX and TX antenna allocated few tens meters one from other and with over KW output RX front end can be not blocked but even damaged ! For AM SWL really one of the best solution is - resonant magnetic loop

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