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Why would one want a GPSDO in their rig?

N8FNR
N8FNR Member ✭✭

I am going to order a 6600 very soon and noted the GPSDO option on the order page. Why would one want this option? I operate 160-6 and do some digital modes including WSJT on all of those bands. What functionality would I gain with the GPSDO?

Zack  N8FNR

Answers

  • Ray Andrews, K9DUR
    Ray Andrews, K9DUR Member ✭✭
    edited June 2017
    Zack,

    You do not gain any functionality.  What you gain is long-term frequency stability/accuracy.

    73, Ray, K9DUR
  • N8FNR
    N8FNR Member ✭✭
    edited June 2020
    Does it help much on 160-6 or just for VHF - microwave stuff?
  • HCampbell  WB4IVF
    HCampbell WB4IVF Member ✭✭
    edited June 2019
    I had the same question when I ordered my 6700, and found the following post, courtesy of K9ZW:

    What is a GPSDO and Why Would I Want One? – by Steve Hicks – N5AC, VP Engineering

    https://k9zw.wordpress.com/2012/10/12/flex-radio-flex-6x00-series-the-gpsdo-gps-disciplined-oscillator-option/

    Howard
  • N8FNR
    N8FNR Member ✭✭
    edited June 2020
    Thanks for the replies Ray and Enos.
  • Ria
    Ria Member ✭✭
    edited November 2019
    For average hams, it's overkill. 

    For power users, it's a valuable tool. You can use it for bragging rights in the ARRL FMT too. 

    Maybe when I get some spare $$$ I'll get one. I considered during initial purchase but decided it wasn't necessary for most of my needs. Instead, WWV calibration with each new software load worked good enough for regular ham use. 

    Oh, and there's also geodiversity whenever that happens. But that seems to be pretty far off their radar for the time being.

    Ria
  • Norm - W7CK
    Norm - W7CK Member ✭✭
    edited June 2017
    I didn't get one either Ria.  One problem I do have is that 2m is way off frequency on my 6700.  I don't know if the GPSDO would have helped with this issue or not.  Its far frequency enough that I vary rarely use it on 2m now.
  • Burch - K4QXX
    Burch - K4QXX Member ✭✭
    edited June 2017
    Mine is not way off but when I talk on 144.200, I have to set the VFO to 144.200.250.  I have an external 10Mhz GPS that corrects this.  There are quite a bit of them for sale on Ebay if you don't mind using an external one.
  • Ria
    Ria Member ✭✭
    edited June 2017
    Yes that would be another use case. However don't feel too bad, when working VHF/UHF I was told that due to the transverters some people are using it was just like HF in the old days - you CQ on a frequency then tune around for the reply. :)
  • Burch - K4QXX
    Burch - K4QXX Member ✭✭
    edited June 2017
    I remember when I first got into VHF/UHF weak signal stuff back in the late 90's.  I had a Yaesu FT-736r with the 222mhz and 1.2ghz modele.  Trying to work stations on 1296.100 you had to tune up and down the band to find them.  Now with a transverter and the Flex, I can find the station in the padadapter.  Much easier! 
  • George KF2T
    George KF2T Member ✭✭✭
    edited June 2020
    It's a big help on 6m with weak-signal digital modes. Also extremely valuable when you have transverters and can use the 10 MHz output to sync your whole system to GPS. For satellites, it's a big help. For weak signal and EME, I wouldn't want to be without it. 

    For general HF SSB/CW and casual digital, it's not a big deal. The rig is plenty stable and accurate without it.


  • Norm - W7CK
    Norm - W7CK Member ✭✭
    edited June 2017
    I'm talking about the 6700 which has 2m built in.  I'm NOT using a transverter.

    Would the GPSDO help in this example?  When using 144.200 I have to have it tuned to something like 144.290 or something close to that in order to actually transmit on 144.200.  I then have to dial in a bit of RIT to receive the station.  It is nearly impossible using the digital modes.

    Very dissatisfied.
  • Burch - K4QXX
    Burch - K4QXX Member ✭✭
    edited June 2017
    I don't use a transverter on 2 meters.  I used to use one on 1296 but I have never run a transverter on 2 meters.  I am using the built in 2 meters on my 6700.   You have a problem if it's off that much.  When I hear stations on 144.200, I have to tune to 144.200.250.  I just recently purchased an external 10Mhz reference because my 6700 was drifting really bad.  I just had it repaired under warranty but using the 10mhz reference gets me back to 144.200.  I don't think it will help you if you are off that much as it sounds like there is a problem if you have to tune to .290 to transmit on .200.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited June 2017
    Norm- there is a defect for this issue, #3333.  The frequency calibration setting is not scaling up properly from the first Nyquist zone to the 2nd one where 2m is located.  Unfortunately, I do not have any information regarding a delivery scheduled only to say it is on the list for an upcoming release (not 2.0.x)
  • Norm - W7CK
    Norm - W7CK Member ✭✭
    edited June 2017
    Thanks Tim.  I bought the 6700 thinking "great it has 2m built in".  Haven't really been able to use it much at all.  Now its 5 years old and still no fix.

    Frustrated.
  • Peter K1PGV
    Peter K1PGV Member ✭✭
    edited May 2018
    Ahhhhhh.... I still "fondly" remember the SDR-1000. During the first hour or so of operation your PSK31 traces would sloooooowly wander to the right.... it was kind of diagonal PSK31.

    Now I'm a fan of the external GPSDO. I like to be dead on the frequency I think I'm on... just as an accuracy thing.

    Peter
    K1PGV
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited June 2017
    Those were the good ole days ;-)
  • philip.theis
    philip.theis Member
    edited June 2017
    I have been using two 6700's on 144 native for some time now. What problem do I have? Haven't noticed it yet.

  • k3Tim
    k3Tim Member ✭✭
    edited June 2017
    For mobile / portable operation it gives one unbelievable frequency accuracy. The man pack for Filed Day I'll be using has the GPS ant set up. Another nice feature is it gives your grid square. Maybe someday it can beat of a network timeserver.
  • Ryan - NC4RA
    Ryan - NC4RA Member ✭✭
    edited April 2019
    I was looking at trying one of the external BG7TBL ones. Was hoping to power it with the shack's power supply instead of adding another wall wart. However the input voltage states 11.7-12.9 Anyone have any experience with running one with 13.6V ?
  • Ray Andrews, K9DUR
    Ray Andrews, K9DUR Member ✭✭
    edited June 2017
    A couple of silicon diodes in series would drop the voltage about 1.4v, making your 13.6VDC supply be 12.4VDC.  -- 73, Ray, K9DUR
  • Ryan - NC4RA
    Ryan - NC4RA Member ✭✭
    edited June 2017
    Great advice!! Thank you guys
  • Ross - K9COX
    Ross - K9COX Member ✭✭
    edited June 2017
    My Heath VF-1 was just fine for AM
  • Bob Brown - N8OB
    edited June 2017
    I'm running mine on 13.8v with no problems.  It is a nice unit that checks out very accurately.  I did not see any reason to add anything else to the radio.  I have used it for FMT and the last one was less than .25 hz off.

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