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IF Shift question

Singularity35

Singularity35

DU7DVE
Jan 16, 2014
425
90
138
Small City, Philippines
From what I understand, the RIT or clarifier control offsets the rx frequency from the tx but what I can't seem to figure out is whether the IF shift control does the same thing or does it shift both tx and rx frequencies? I'd appreciate any input about this. Thank you in advance.
 

Think of the IF as a large window. Now take a smaller window and hold it in front of the larger window. This smaller window is the actual passband of your receiver's IF stage. As you move the smaller window from side to side you shift what you can see (or hear) within the entire IF window. The bandwidth remains the same however you shift it from side to side of your center carrier frequency Another control usually used in conjunction with IF shift is Pass Band Tuning or PBT. It widens or narrows the width of the smaller window so to speak. IF Shift helps when you have an interfering station close and you can move the IF response so that it falls outside the passband window.
 
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wavrider said:
http://www.robkalmeijer.nl/techniek...hniek/hambladen/qst/2001/03/page44/index.html

technical but it explains it pretty good
Click to expand...

I don't really like that article. The author refers to IF Shift and Pass Band Tuning as being the same thing but they are not.

"Figure 8-Situation 4, using a TS-440S with passband tuning (IF shift)."

IF Shift maintains the same bandwidth but shifts it from side to side of the carrier frequency while Pass Band Tuning changes the width of the IF filter while keeping it in the same spot in relation to the carrier frequency.
 
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Thanks for the quick replies.

Does that mean that where I set my high pass and low pass of the DBF in my FT857 will be a factor in how wide my passband is? It's probably just my ear or how I use the IF shift because I'm only noticing slight improvements in rx but not as much as using RIT.

The reason I'm asking is that I get the best audio reports during ragchews when I set my frequency at .05 Mhz higher than the center frequency and I'm using RIT to listen on the center frequency. Should I use IF shift or continue using RIT? Also, will my tx audio be affected by the settings on my band pass?
 
sounds like someones radio is off frequency, maybe yours or the people your talking with, check your radio frequency alignment against wwv at 5,10,15,20 or 25mhz
 
Last edited:
IF shift doesn't change your frequency. It shifts the pass"window" like ck said. You use it to move away from adjacent frequency interference.It will change the tone and you can use it to tailor the sound to suit yourself ,but it has nothing to due with RIT. Use your rit as you normally do. If you have to constantly use RIT your radio is off frequency.
 
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The DSP filters in the 857 are audio filters and not RF or IF filters so they function differently to accomplish what sounds like the same thing even though it is not the same. I think I said that right. :confused:
 
vkrules said:
You can adjust the lsb and usb tx and rx offsets separately in the menu if needed . (don't know the item no)
Click to expand...

Captain Kilowatt said:
You CAN but you probably really shouldn't.
Click to expand...

If you mean messing around with the "hidden menu", I probably won't. I have played around with the carrier point settings. Changing to -100 on the LSB resulted in audio reports saying I had "penetrating" audio with high intelligibility(which I prefer) but a lot of people in the local ragchew group prefer the deep, bassy audio.

I have the LSB transmit setting now at +200 which seems to be more pleasing to listeners. I do have to get a monitor at some point so I can listen to myself. I had somebody record my audio when it was still "penetrating" and it was not unpleasant to me. I still have to have somebody record it now and compare. It seems that the ragchew group will admire penetrating audio only if it's coming from a high end mic and routed through a console(ham equivalent to a butt dyno for car enthusiasts?). If I do say so myself, my penetrating audio wasn't too far off from the "loaded" audio but I don't have to listen to myself and I try to please. :)
 
Sorry for butting in but I think the thread is concluded anyway I was wondering if it is possible to convert an IF shift into an rf notch by building an rf notch circuit on some circuit board and mounting it on an optional crystal filter empty position in an analog radio.
 
Captain Kilowatt said:
Think of the IF as a large window. Now take a smaller window and hold it in front of the larger window. This smaller window is the actual passband of your receiver's IF stage. As you move the smaller window from side to side you shift what you can see (or hear) within the entire IF window. The bandwidth remains the same however you shift it from side to side of your center carrier frequency Another control usually used in conjunction with IF shift is Pass Band Tuning or PBT. It widens or narrows the width of the smaller window so to speak. IF Shift helps when you have an interfering station close and you can move the IF response so that it falls outside the passband window.
Click to expand...

That's neat way to describe how it works. I have found with my new-to-me TS830, using a combination of IF shift, PBT, and notch filter really cleans people's signals up and makes them sound great.

And singularity35, I've also found that despite the fact most guys are running newer rigs, they all receive differently. I play on 40 meters with a bunch of audio guys, and they all have differing opinions as to what sounds best through their headphones or monitor. I'd make sure you are aligned via WWV (which should be in your manual... but I never use those things. ;) If it's off as little as you say, it's probably not worth messing with for sending it in for alignment.

73,
Brett
 

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