Default IF Width on 6 meter CW


Barry D. Jacobson
 

Hi, tried to enter the VHF contest tonite. Have only an indoor 6/2/70 cm mag-mount indoors for VHF. I know it is bad news as needs to be outdoors and horizontally polarized. But tried to give it a shot anyway. Couldn't hear a soul. Tried to fiddle with IF width to quiet background noise. Noticed that it was on 600 Hz originally. On HF I always thought default was 300 Hz. Don't remember changing it. Is this normal for 50 MHz band?

BTW, Heard from Dave Sumner K1ZZ by email that propagation was lousy today and even he gave up with good antenna.

73,

Barry WA2VIU

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd


Rejean Leveille
 

Hi Barry
The radio will remember your 3 band registers filter bandwidth 300 (optional) to 12 kHz regardless of your selected mode. You need to manually select one and it is not automatically adjusted when you change the IF width unlike the FTdx5000 who got an auto mode.
Strong 6 m opening on Sunday morning,,, contest

73, Rejean, va2am


Carl Yaffey
 

I had plenty to work using FT8. But I only heard a loud 5 on SSB and a faint one on CW.

Carl Yaffey  K8NU
614 268 6353, Columbus OH
http://www.carl-yaffey.com
http://www.bluesswing.com
http://www.timbrewolvesband.com
http://www.folkramblers.carl-yaffey.com
Http:www.clintonvillegrass.com


On Jun 12, 2021, at 11:21 PM, Barry D. Jacobson <bdj@...> wrote:

Hi, tried to enter the VHF contest tonite. Have only an indoor 6/2/70 cm mag-mount indoors for VHF. I know it is bad news as needs to be outdoors and horizontally polarized. But tried to give it a shot anyway. Couldn't hear a soul. Tried to fiddle with IF width to quiet background noise. Noticed that it was on 600 Hz originally. On HF I always thought default was 300 Hz. Don't remember changing it. Is this normal for 50 MHz band?

BTW, Heard from Dave Sumner K1ZZ by email that propagation was lousy today and even he gave up with good antenna.

73,

Barry WA2VIU

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd


Barry D. Jacobson
 

Can anybody confirm what default CW IF width setting is on 50 MHz band? Was puzzled when I saw 600 Hz instead of usual 300.

Thanks.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd


On Sun, Jun 13, 2021, 9:16 AM Carl Yaffey via groups.io <cyaffey=gmail.com@groups.io> wrote:
I had plenty to work using FT8. But I only heard a loud 5 on SSB and a faint one on CW.


On Jun 12, 2021, at 11:21 PM, Barry D. Jacobson <bdj@...> wrote:

Hi, tried to enter the VHF contest tonite. Have only an indoor 6/2/70 cm mag-mount indoors for VHF. I know it is bad news as needs to be outdoors and horizontally polarized. But tried to give it a shot anyway. Couldn't hear a soul. Tried to fiddle with IF width to quiet background noise. Noticed that it was on 600 Hz originally. On HF I always thought default was 300 Hz. Don't remember changing it. Is this normal for 50 MHz band?

BTW, Heard from Dave Sumner K1ZZ by email that propagation was lousy today and even he gave up with good antenna.

73,

Barry WA2VIU

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd


Carl Yaffey
 

600 hz here as well.
Carl Yaffey  K8NU
614 268 6353, Columbus OH
http://www.carl-yaffey.com
http://www.bluesswing.com
http://www.timbrewolvesband.com
http://www.folkramblers.carl-yaffey.com
Http:www.clintonvillegrass.com


On Jun 13, 2021, at 9:19 AM, Barry D. Jacobson <bdj@...> wrote:

Can anybody confirm what default CW IF width setting is on 50 MHz band? Was puzzled when I saw 600 Hz instead of usual 300.

Thanks.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd

On Sun, Jun 13, 2021, 9:16 AM Carl Yaffey via groups.io <cyaffey=gmail.com@groups.io> wrote:
I had plenty to work using FT8. But I only heard a loud 5 on SSB and a faint one on CW.


On Jun 12, 2021, at 11:21 PM, Barry D. Jacobson <bdj@...> wrote:

Hi, tried to enter the VHF contest tonite. Have only an indoor 6/2/70 cm mag-mount indoors for VHF. I know it is bad news as needs to be outdoors and horizontally polarized. But tried to give it a shot anyway. Couldn't hear a soul. Tried to fiddle with IF width to quiet background noise. Noticed that it was on 600 Hz originally. On HF I always thought default was 300 Hz. Don't remember changing it. Is this normal for 50 MHz band?

BTW, Heard from Dave Sumner K1ZZ by email that propagation was lousy today and even he gave up with good antenna.

73,

Barry WA2VIU

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd





Barry D. Jacobson
 

Ok thanks. Wondering if there is any special reason for that. I am total novice on VHF.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd

On Sun, Jun 13, 2021, 9:22 AM Carl Yaffey via groups.io <cyaffey=gmail.com@groups.io> wrote:
600 hz here as well.

On Jun 13, 2021, at 9:19 AM, Barry D. Jacobson <bdj@...> wrote:

Can anybody confirm what default CW IF width setting is on 50 MHz band? Was puzzled when I saw 600 Hz instead of usual 300.

Thanks.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd

On Sun, Jun 13, 2021, 9:16 AM Carl Yaffey via groups.io <cyaffey=gmail.com@groups.io> wrote:
I had plenty to work using FT8. But I only heard a loud 5 on SSB and a faint one on CW.


On Jun 12, 2021, at 11:21 PM, Barry D. Jacobson <bdj@...> wrote:

Hi, tried to enter the VHF contest tonite. Have only an indoor 6/2/70 cm mag-mount indoors for VHF. I know it is bad news as needs to be outdoors and horizontally polarized. But tried to give it a shot anyway. Couldn't hear a soul. Tried to fiddle with IF width to quiet background noise. Noticed that it was on 600 Hz originally. On HF I always thought default was 300 Hz. Don't remember changing it. Is this normal for 50 MHz band?

BTW, Heard from Dave Sumner K1ZZ by email that propagation was lousy today and even he gave up with good antenna.

73,

Barry WA2VIU

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd





Lou W7HV
 

The bandwidth will be whatever you left it at in each of the three stack registers.  It'll only be the default after a factory reset, or if you haven't changed it since the last factory reset. What the factory default is is irrelevant.  Set the bandwidth (roofing filter and IF DSP WIDTH control) as desired for the intended operation and current conditions.  300, 600, 1200, 3000 can all be usable for CW depending on what you're doing. I like the wider widths for tuning around and listening to what's going on on the band.  QSOs will generally be done with 600 or maybe 300 in noisy or crowded cndx.

Atmospheric band noise goes down on higher bands.  It's really loud on 160 and 80m, much less on 20,15, 10m, and much less than that on 6m.  It also depends on time of day and propagation condx. The goal should always be to get band noise to be ~2x the RX noise floor.  This reduces the load on the RX's front end and improves performance.  Turn preamps off, engage IPO, and switch in attenuation (all those controls are there for a reason) on the lower bands as needed get band noise to just dominate the rigs noise floor.  Turning down RF gain can also be beneficial.   On high bands were the band noise is much less, engaging the preamps can be appropriate.  Again, the goal is to get the band noise to just dominate the RX noise floor. 


Barry D. Jacobson
 

How do you check the RF noise floor? Pull out antenna wire? Use dummy load?

Thanks.

--
Barry Jacobson
WA2VIU
bdj@...
@bdj_phd


On Sun, Jun 13, 2021, 9:39 AM Lou W7HV via groups.io <louandzip=yahoo.com@groups.io> wrote:
The bandwidth will be whatever you left it at in each of the three stack registers.  It'll only be the default after a factory reset, or if you haven't changed it since the last factory reset. What the factory default is is irrelevant.  Set the bandwidth (roofing filter and IF DSP WIDTH control) as desired for the intended operation and current conditions.  300, 600, 1200, 3000 can all be usable for CW depending on what you're doing. I like the wider widths for tuning around and listening to what's going on on the band.  QSOs will generally be done with 600 or maybe 300 in noisy or crowded cndx.

Atmospheric band noise goes down on higher bands.  It's really loud on 160 and 80m, much less on 20,15, 10m, and much less than that on 6m.  It also depends on time of day and propagation condx. The goal should always be to get band noise to be ~2x the RX noise floor.  This reduces the load on the RX's front end and improves performance.  Turn preamps off, engage IPO, and switch in attenuation (all those controls are there for a reason) on the lower bands as needed get band noise to just dominate the rigs noise floor.  Turning down RF gain can also be beneficial.   On high bands were the band noise is much less, engaging the preamps can be appropriate.  Again, the goal is to get the band noise to just dominate the RX noise floor. 


Jim Jerzycke
 

A dummy load would allow you to see the noise floor of the receiver. This will give you a reference point to start at. See how much it comes up after you put the rig back on the antenna, and you get a rough estimate of what it is *with your receiver*. This is plenty good for most folks, and you can then experiment with the filters, preamps, etc.

As far as measuring the actual "band noise", that would take some pretty sophisticated equipment!

73, Jim  KQ0EA


Lou W7HV
 

Yeah.  Ideally you'd switch between a dummy and your antenna to hear the increase in noise from the noise floor of the RX to the band noise.  However,  on my rigs, including the FTDX101MP, the RX noise floor is  the same with the antenna connector open, shorted, or connected to a dummy.  This means you can quickly compare the RX noise floor to the band noise by switching from an open antenna port to the actual antenna.

Of course you don't want to accidentally TX into an open or shorted antenna connector.  If you do, the rig will protect itself, but it's not a good idea to depend on that.