144MHz support on the 6700 with SmartSDR1.9.13

Nick Shaxted

I have been trying to integrate a new transverter this weekend and have noticed that SmartSDR v1.9.13 on Windows 10 does not handle selecting 144MHz at all on my Flex 6700.The software either hangs and fails to select the 144MHz band when asked directly, or the application crashes when I select it as a transverter with 144MHz IF.

Downgrading to SmartSDR v1.9.9 seems to work normally so looks to be a feature added in the latest release.

Can anyone else confirm the observation?

regards
Nick - dl4ogi 

EA4GLI

I tried Nick and I cannot recreate your error.
I can create a 70cm transverter with 144 MHz IF without a problem.

After the upgrade to 1.9.13 I had some odd behaviors that shorted out with a Factory Reset.

• Hold the OK button in the front panel while you turn ON the 6700-6500
• A count down from 5 starts
• Hold the OK button until it reaches 0
• That will start the Reset process

Remember to save your profiles and settings.

pa0bie

I have no problem with 144 MHz , direct into a PA and through XVTR with 1.9.13.

W0DHB

I do not see the problem with 2m here Nick. Dave W0DHB

Nick Shaxted

Thanks for all the replies.
After carrying a Factory Reset I found I could select 144MHz again.
Sadly following the discovery of the CW QSK "feature" last week my 144MHz portion no longer works. Well, more to the point, it is deaf -- barely hear an handheld from the other side of the apartment.

Nick dl4ogi/gm4ogi

EA4GLI

144 doesnt work on the Flex radio or you busted a preamp?

Tim - W4TME

Nick - if you are still experiencing the issue, please submit a HelpDesk support ticket (http://helpdesk.flexradio.com)

Nick Shaxted

Following up further on this issue, the fault appears to have been a hardware related. The failure of relays to switch probably caused the software to hang. The 6700 has been fixed and appears fully operational.

Nick dl4ogi/gm4ogi

Norm - W7CK

I'm confused.  The 6700 has 144 Mhz built in so why would you use an external 144 Mhz transverter?

Jose B Rivera

Looking at the 6700 specifictions it seems it only receives 144Mhz. It does not transmit on that band.

Marc Lalonde

6700 transmit via XVTR port  whit  ~13dBm

144 was popular IF for microwave transverter 

Tim - W4TME

To transmit on 2m at a power level higher than ~13 dBm (20 mW)

Nick Shaxted

The reason for using a real transverter is manifold, the main ones are detailed below.

To drive the 3cm transverter which is monted remotely on the dish I need to produce about 1w at 144MHz. You can't do this directly with the 6700 and I would be a little unhappy pushing the maximum power levels anyway. I think at 144MHz the power is limited to +8dBm anyway with it being higher at lower frequencies. Either way not enough for my system.

As a true microwaver I am used dealing with very weak signal signals so look to whatever method I can to allow me to find that extra 0.25dB or less and have the best "radio" signal resolution the 6700 is able to offer. The advantage of using 28MHz as the IF and driving from there is that I am able to exploit the full potential of the fft bin size (1.25Hz), at 144MHz the fft bin size is larger and therefore weak signals are smeared across into adjacent bins and resolution is lost (and, it can be argued, ultimate sensitivity).

I have 23cm, 13cm, 9cm and 3cm transverters. As the system (antenna, transverter chain and hf chain) was designed (not lashed up) with 28MHz IF in mind (originally an FT-1000mp) so as not to invalidate years of results by radically changing I felt it desirable to keep the same solution. Clearly a small rebalancing of overall system gain and its distribution was required but this was minimal compared to using the 6700 native144MHz solution.

One of the options still is to use an 0Hz IF transverter which can give me a little highly controllable receive gain but also to give me extra power of up to about 4w. This is a Winter project but ultimately will restrict me to the performance of the native 144MHz portion but it is more likely that I will introduce the same 0Hz IF solution for 70MHz where the transmit power is similarly restricted on the tvtr port and external noise is the limiting factor..


regards
Nick dl4ogi/gm4ogi

Marc Lalonde

as for boost the VHF output  look 
http://www.minikits.com.au/electronic-kits/rf-amplifiers/rf-high-power/2m-8W-Amplifier

i use it for drive 1KW  W6PQL brick  from XVTR

as for bin resolution 1.25 or 3 HZ resolution  did it really matter ??  as long as you have good LNA  ?

and 28MHz if was usually to low for filter the LO leack and have clean TX

73!

Norm - W7CK

Thanks Tim.  I'm using the 75 watt DEMI LDPA.  It never dawned on me to use a separate transverter.  I guess the nice thing about using the transverter is that it would be possible to program in an offset so that the radio would be on frequency.  I don't believe this is possible with the LDPA.