Is 137mhz Weather Satellite reception possible with the Flex-6700?

KF4HR

If I'm reading the specifications correctly the 6700 should be able to receive from 135 to 165mhz, but my 6700 doesn't seem to want to let me tune much lower than about 140mhz.  When I get to about 140mhz and the receiver jumps to the 72mhz range.  And I can't input the 137mhz frequencies directly either.  Is my 6700 defective or am I missing something?  Ideally I'd like to monitor Weather Satellite downlink frequencies in the 137mhz range.  

Butch - KF4HR

Norm - W7CK

I'm not able to try it right now but when you selected the band did you select GEN?  I'm assuming that's for General Coverage.  I've never tried it but you'd think General Coverage mode would let you receive any frequency between the ham bands.

KF4HR

Hi Norm - No, selecting GEN doesn't do it.  The lowest frequency I can input manually is 140.000mhz, and if I slide the grid to the right slightly (to try to tune below 140mhz) the frequency jumps to the lower VHF range (60-70mhz range). 

I'd be interested in knowing whether other 6700 owners can tune to the below 140mhz.  Being new to the Flex I'm not sure if there's a querk in the software that needs to be looked into, or if my unit is defective.

Roy Laufer

My 6700 seems to able to do it. The frequency is very quiet for my QTH (S1-2 noise floor).  You might want to zoom into your particular panadapter - if the visualized panadapter bandwidth is too wide SSDR starts to do wacky things to hide the fact that below 135MHz the earth is flat and we all fall off of it (and there be dragons too!)...

But seriously, zoom into the panadapter and you should be able to see 137MHz!

Good luck!

KF4HR

Thank Roy.  You're correct, I did have my panadapter too wide.  Once I narrowed my panadapter I was able to tune down to the 137mhz weather satellite frequencies, unfortunately I realized there was no way to widen the FM bandwidth to the necessary 30-40khz to copy the weather birds, so it looks like I'll be hanging on to my Hamtronics Weather Receiver.     

Marc Lalonde

That may good to put it on praise list   ,it a really good use of one of the 8 receiver slice ;-)

Norm - W7CK

I managed to get down to 136.0 Mhz and then it jumped to 73.9.  I now have a slice at 136.0 that I can't get rid of and I can no longer get to 2 meters.  Every time I select 2m, it jumps to 73.9 Mhz.  Even if I load a different profile, it still has slice at 136.0 and I can't delete it or move it.   Darn frustrating.....

KF4HR

Norm - Same situation here. And I found once the VHF slice jumps into the 70mhz range I couldn't scroll back into the higher VHF range.  Hopefully v1.6 will fix these issues. 

To get your VHF Slice back to the 2M band, enter a 2M frequency manually and press Enter.  That worked for me. 

Butch - KF4HR   

Norm - W7CK

Thanks Butch.  It didn't work for me.  I had to do a factory reset and them import my profiles.   I use 2m quite a bit and the flex has been a tad frustrating to say the least.  I'm hoping it gets resolved in v1.6 as well but when I asked about it, I didn't get a warm and fuzzy feeling it was going to be addressed anytime soon.   Focus seems to be on contesting?  Not sure.

KF4HR

Norm - Wow, you had to do a factory reset?  I guess that VHF tuning really did hang up your Flex. There are definitely some bugs with this VHF slice situation.  When I have several other slices open on HF, then open a 2M slice my HF slice frequencies disappear and I have to reset the frequency on each HF slice. Do you notice this on yours?

Being new to the Flex I sometimes have a hard time differentiating between a known software issue and whether my Flex has a problem.  I've love to see Flex put out with a known bug list so at least I'd know for sure.  On the bright side, I've found the pluses of my Flex far out weighs its (hopefully soon to be fixed) software issues.

My focus is mainly EME and Satellites, although I have been known to do a bit of VHF and above contesting.  I only jump into HF contests when I need a particular prefix for my country count, and more importantly, I have a supply of Excedrin on hand. 59 QSL? :^))

Butch
KF4HR

Roy Laufer

There are some quirks with the 6700 operating beyond 73.9MHz that FRS is very well aware of, but seem to find it difficult to squash. The 6700 performs a few "tricks" at 2 meters - the ADC samples at 245 million samples per second, which usually means that it can only accurately digitize signals of one half the sampling rate or less. This would be 122MHz! The way FRS gets around this (I assume) is to play around with the software filters and "fold" the 2 meter signal into the lower frequency but manipulate it as the harmonic. When this digital juggling works, it gets the job done well. Occasionally the 6700 drops everything onto the floor and you have to start all the plates spinning and the objects getting juggled. I hope that FRS can improve the juggling act, but at this point I am not sure that they can protect us from everything falling down 100% of the time. This, of course, is all conjecture on my part, as I try to build a consistent sense of how the 6700 does its magic...