Translator protection

I have a question:  I'm working on an app for someone.  A channel is available but it's listed as a receive frequency (co-channel)  for a translator that is still just an application.  This translaotor is just 8 km from our proposed site, but is not in the "key hole" direction this translator would be receiving in.

 

Now this translator lists a primary station that I seriously doubt could be received over the air.  (The primary is like 130 miles away) but nonetheless it's the listed primary.

 

So my question is would it be best to not use this frequency to avoid any issues?  I mean our LPFM would drown out any signal that primary is putting into this community.

 

Also I thought Rfree tells you when you have an issue like this?  Rfree shows no such issue.  I had to find it with a modified version of Google Earth.  What is the exact rule on translator protection and does one create an exhibit showing no interference to translator reception?

Comments

paulbame

translator input protection and RFree

Translator inputs show up as pseudo stations on RFree's frequency details page, and their callsign looks roughly like this:

K222AC(KLMN)

which represents the off-air third-adjacent input channel of K222AC receiving KLMN.  These are actually pretty rare in the searches I've been doing.  If you get one, click on it (in advanced mode anyway) and you'll get a map with the keyhole and all 3 stations on it, and signal strengths of both KLMN at K222AC and that of your LPFM too.  That forms the basis for the first type of waiver (34dB U/D) described in 73.827.

Also if that K222AC (there may be more than one, LIC, CP, etc) is the result of late-filed data, there will be a little help icon next to it which describes that situation.

I should mention that there are some pretty fantastical and also missing pieces in the translator input-protection part of CDBS.  So bad we at Prometheus wrote the FCC a long boring analysis letter about it.

             -p

it-rf-consulting

Translator App filed after cutoff date?

Hello,

   The primary question here is; when did the primary station file the translator App? If it is after the cutoff date, then they are precluded and your LPFM app has priority. If you are not in ther keyhole then an exhibit showing and proving that you would not cause interference will be sufficient to allow your LPFM App to be accepted for filing, and barring any other issues, to be granted. You need to run a frequency study on REC network and get more supporting data. Corp. commercial stations that are NOT local, are filing translator Apps to grab up all remaining frequencies and prevent LPFM's from getting a channel. Do the neccessary engineering work and FILE!!! The burden is on them if they filed that translator App. after the cutoff date. GOOD LUCK!

Peace...

 

Sincerely,

IT-RF-Consulting