BCD325P2 vs BCD436HP Close Call

[UPMan]

Ideally you would inject two signals. One to provide a solid "floor" then slowly increase the 2nd frequency (in the same band) until it triggers. Close call triggers when a signal is a certain dB above either the noise floor or the strongest other signal in the band. In the real world, since an antenna can affect signal amplitude, an external antenna can affect close call range. One example from my experience is that I've never gotten a CC hit from an aircraft on an on-unit antenna but have gotten many on an external antenna. The antenna raised the target signal level much more than it raised the noise floor.

 

[KevinC]

Ideally you would inject two signals. One to provide a solid "floor" then slowly increase the 2nd frequency (in the same band) until it triggers. Close call triggers when a signal is a certain dB above either the noise floor or the strongest other signal in the band. In the real world, since an antenna can affect signal amplitude, an external antenna can affect close call range. One example from my experience is that I've never gotten a CC hit from an aircraft on an on-unit antenna but have gotten many on an external antenna. The antenna raised the target signal level much more than it raised the noise floor.

And if my radio didn't have this design flaw I would have never needed to know that information.

 

[KevinC]

Bottom line is the missing cap C1/noise issue is a major issue and not "way overblown" as someone else stated.

 

[scannersnstuff]

Ok, I have a question. When my batteries were in the 436, I did not have a clock issue. I removed them, and stored away the radio, for about a month. When I repowered, I had lost the date/clock. Is this normal, if you have c1 installed ?.

 

[jonwienke]

That is totally normal. The tiny RTC backup battery only lasts a week or two if the main batteries are removed.

C1 has nothing to do with the clock, other than being on the same circuit board.

 

[jonwienke]

Bottom line is the missing cap C1/noise issue is a major issue and not "way overblown" as someone else stated.

For Close Call hits, yes. For regular reception, not so much, as long as the antenna is physically separated from the battery compartment.

 

[KevinC]

For Close Call hits, yes. For regular reception, not so much, as long as the antenna is physically separated from the battery compartment.

How silly of me, everyone should use one of these when going portable then...

http://mizzoumagarchives.missouri.e...ggle-for-signal/images/feat-antennas-is-2.jpg

Or for simulcast this one...

https://forums.radioreference.com/a...62610-needs-discone-head-mount-helmetyagi.jpg

 

[jonwienke]

A Diamond RH77CA with the Uniden SMA-BNC adapter is sufficient, but you be you.

 

[KevinC]

A Diamond RH77CA with the Uniden SMA-BNC adapter is sufficient, but you be you.

No Jon it isn't. I've done extensive testing on this. What would be sufficient would be if Uniden admitted that this is an issue.

And even if it did it would do "Zip. Zilch. Nada" for Close Call.

But you be you and keep defending Uniden no matter what.

 

[KevinC]

In the words of UPMan...

When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.
If necessary, check with legal or senior management before commenting.
Never promise a fix you cannot deliver.

http://info.uniden.com/twiki/pub/publish/upman.html

 

[a29zuk]

How silly of me, everyone should use one of these when going portable then...

http://mizzoumagarchives.missouri.e...ggle-for-signal/images/feat-antennas-is-2.jpg

Or for simulcast this one...

https://forums.radioreference.com/a...62610-needs-discone-head-mount-helmetyagi.jpg

LOL!

 

[KevinC]

Anyway, I've proven my point so I'm done here.

Thanks for playing along everyone.

 

[k3fs]

I agree Kevin.

For regular reception the BNC adapter is not even close to being enough. You need a few more inches of separation of the antenna from the radio to clear this noise issue. I have used different methods to test this out. Aluminum or copper tape fixes UHF, but not so much VHF.

C1 fixes both of these.

Funny, how someone named Paul O. admitted to the issue on a local scanner group. Yet, there are others ready to deny this issue.

Close call hits have increased since I installed the C1 capacitor myself.

False advertising and not delivering what you promise are problems.

When there is a problem, admit it as soon as possible.
Customers are not stupid. Ignoring or denying a legitimate problem is not the way to handle it.

You loose credibility when you don't follow your own rules.