IF Frequencies for 536 and HP-1

[JimQ]

Does anyone know the IF frequencies for the BCD536-HP and the HP-1? I ask because I am getting a lot of interference in the railroad band... 161.52 MHz is particularly annoying since that is the Train-Dispatch frequency for Pan Am Railways in my area...

I also pick up weather frequency signals [don't know which ones yet] in the RR band but the WX interference does not last long..

Also, what kind of IF do these have: single, double or triple conversion? Hopefully, this info will help in my troubleshooting...

 

[kruser]

Does anyone know the IF frequencies for the BCD536-HP and the HP-1? I ask because I am getting a lot of interference in the railroad band... 161.52 MHz is particularly annoying since that is the Train-Dispatch frequency for Pan Am Railways in my area...

I also pick up weather frequency signals [don't know which ones yet] in the RR band but the WX interference does not last long..

Also, what kind of IF do these have: single, double or triple conversion? Hopefully, this info will help in my troubleshooting...

I recall a thread about this and the HP-1 but I don't think it was totally confirmed when the thread went dead. Sorry I don't have a link.

They should all be triple conversion though.

For your problem, have you tried using the IF Exchange feature?
I think that is turned on/off in the 4/536 models with Function and 7.

It just shifts one of the IF frequencies slightly and will often remove an interfering signal or image.
I don't recall if the HP-1 had that feature but it could as it was introduced in at least the XT series like the 996XT.

Your other option is a WX band notch filter from places like PAR Electronics.
They work well but could attenuate the upper portion of the RR band but not by a lot.

If you can ID the frequency that is messing with 161.52, PAR can tune a notch filter centered on the offending frequency.

I'd try the IF exchange feature first though as that may just do the trick if you have 161.52 programmed in as a conventional frequency. I don't recall if the IF exchange feature works in say a limit search from the bottom to the top of the rail band, never tried it in a limit search before.

 

[JimQ]

kruser, thank you for the suggestions; I'll give the ifx function a try... I have been thinking about trying that but have been under the impression that it only works in hold mode... But it's worth a try... I'll also look into the filter... I'll post any results I get...

 

[kruser]

kruser, thank you for the suggestions; I'll give the ifx function a try... I have been thinking about trying that but have been under the impression that it only works in hold mode... But it's worth a try... I'll also look into the filter... I'll post any results I get...

You may be correct that ifx only works in hold mode.
I looked at my railroad favorite list and found that there is no way to set ifx on or off for each channel in Sentinel.
IFX must be set by editing the Profile where you enter the actual frequency you want ifx to apply to. Weather the radio sees that when scanning a favorite list is unknown but I would tend to think it does check the IFX table stored in the profile each time it scans the frequencies you entered into the ifx part of the profile.

I've only used the function button and 7 to turn on/off ifx. The 536HP does seem to store that value as it is still set after I power cycle the radio.
I'll have to read the radio into Sentinel and see if my test ifx frequencies show up in the profile.

edit: I set IFX to ON for several of my railroad channels in my rail favorite list. I then read the radio into Sentinel and it did populate all those frequencies under the IFX settings under the Miscellaneous tab for my active profile.
So yes, IFX can be used for any frequency you enter into the IFX part of the profile or for those you hold on a bad channel and turn IFX on via the Function and 7 combo. When you read the radio into Sentinel, it will list all the frequencies in your profile where you have turned IFX on.
The radios display will also show IFX if it stops on a channel that you have activated IFX on.

Hopefully that will cure your problem.

 

[Robertolson]

I've had the same issue's on the RR Band with all my Scanners, Until I got a J Pole antenna

That was specially tuned to the RR Band, The Tuned RR band really helps eliminating all outside Interference Garbage, that I got on my All Band antenna.

you will also get way better coverage to.