I.F. specifications rarer than..........

[AlphaFive]

I have spent a week trying to locate information on I.F. specifications for the 536 HP. I have searched countless posts about the subject. I usually find the same question I have, but then no specific answer from anyone, and the subject drifts off in the threads. I have tried to work with Uniden Tech support. As of yet I have no reply. That's okay, I realize they have more important questions than mine to deal with. No knock on Uniden. The manual is lacking the specific information I'm looking for. Is the unit using triple conversion? What are the specific numbers for up and down calculations? Also, I fully realize the unit utilizes Intermediate Frequency Exchange.
I simply want to know, if the scanner stops on say, 148.xxxx, and the transmission doesn't belong there, where do I look on the spectrum for the true source.... hellllllppp.

 

[nr2d]

You didn't search to much. Even though this tread is concerning the BCD436HP UOMAN makes this statement "All ours are triple." True it doesn't give the IF frequencies but it gives you a place to start looking.

http://forums.radioreference.com/uniden-tech-support/324349-triple-conversion.html

 

[unusedusername]

Uniden BCD536HP Frequency Coverage

It isn't an authoritative source, but I've been using it to validate input frequencies for this that the 436/536 can handle.

I don't believe there is anything more detailed that is published publicly.

 

[AlphaFive]

I.F. specifications

Thank you both for your reply. I do appreciate it. If there is some possibility that Uniden I.F. specifications are closely held by them, that is completely understandable, and totally appropriate. The odd thing though is Radio Shack, (GRE), etc.., are completely public with that information. What is so different, engineering wise, that Uniden says to themselves "we need to hold on to this"? Did they stumble onto something like perpetual motion.... It's just weird, I know I can't be the only one who is not be able to locate the specifics, and I am CERTAINLY not so bright as to be the first person to look for this.
Thanks again, take care.

 

[AlphaFive]

I.F. specifications

THANK YOU to boatanchor......... I found this in another thread. 'Uniden seems to use the same IF structure in all of their recent digital scanners, including the X96xt, HP1&2 and the x36HP line.

1st IF @ 380/265Mhz (dual 1st IF's depending on the band being monitored) - Which are routed through either a 380Mhz or 265Mhz SAW filter (basically a ~10Mhz wide 'roofing' filter).

2nd IF 10.8Mhz - Which is routed through either a +-15Khz wide single pole crystal filter for FM, NFM and AM, or a +-100Khz wide ceramic filter for FMB/FMW).

&

3rd IF 450Khz - Which is routed through either a +-4.5Khz ceramic filter for FMN or +-9Khz ceramic filter for FM and AM. The x36HP is the only current Uniden scanner that incorporates separate 450Khz filters for FM/AM and FMN.'


That is what I was looking for.

 

[MStep]

The days of finding schematics in with a comprehensive service manual along with an actual users manual that makes any sense are long gone. In it's place are somewhat poorly written instruction manuals that miss a lot of the important operational information along with radios that contain circuit boards covered with dark epoxy hiding key parts, mostly in the name of you not restoring the cellular band, but really protecting proprietary information regarding the operation of the radio. It's what we have to accept in the cloak & dagger world of the 21st Century--- it's not unusual that Uniden wants to protect its work and hide as much from potential competitors as possible, You can bet that Whistler probably has 2 or 3 of each of Uniden's scanners taken apart in their own labs to see how they work and try to reverse engineer some of the circuitry for use in their own products--- that's certainly what I would do if I were a competitor.

But I say more power to Uniden--- the 436 and 536 are great radios and at reasonable price considering all you're getting. So let them have their little secrets, as long as they can keep rolling those great radios off the production line at prices we can afford.

 

[AlphaFive]

I.F. specifications

Roger that...now that I have something to calculate, I'll be occupied for awhile figuring out where a few miscreant frequencies actually belong.. It keeps me out of trouble, haaaa, take care, happy listening

 

[nr2d]

I know in the radios I come across in my job, the FAA air/ground comm, we use a simple formula (2*IF) + victim frequency = the interference source frequency. I'm 99% sure our receivers are dual conversion. Is this method the same for the same for triple conversion receivers?

 

[UPMan]

1st Heterodyne:
25.000-319.995 MHz : Upper Heterodyne 380.75 MHz
320.000-511-995 MHz : Upper Heterodyne 265.55 MHz
758.000-805.995 MHz: Lower Heterodyne 265.55 MHz
806.000-1300.000 MHz: Lower Heterodyne 380.75 MHz

2nd Heterodyne:
25.000-319.995 MHz: Lower Heterodyne 10.800 MHz
320.000-805.995 MHz: Upper Heterodyne 10.800 MHz
806.000-1300.000 MHz: Lower Heterodyne 10.800 MHz

3rd Heterodyne:
All Bands: Lower Heterodyne 450 kHz

 

[AlphaFive]

I.F. specifications

Beautiful! Thank you very much. Oh well, I guess my Uniden 'perpetual motion' discovery theory is out the window. Everyone have a quiet enjoyable day.