SB County Search

[retiredFD07]

417.575 is active with searchers checking mine shafts. They mentioned mine teams from L.A. County and San Bernardino County. Currently searching the Rosa Peru mine, wherever that is. I haven't confirmed whether this is a BLM freq or Joshua Tree NP freq.

A couple of days ago I saw in the local news that there was a search going in the Yucca Valley area on for a missing 29 Palms teenager. Wondering if this is that search.

<>< Mike
Monitoring from western Riverside County

[retiredFD07]

They just mentioned Black Eagle Mine Road, which runs through Joshua Tree NP. Also just heard "San Bernardino on park net", mentioned switching to a BLM channel.

[sp1989]

Are you using and outside antenna? I'm not hearing anything in Hemet, but don't have an roof mounted antenna yet.

[cvrules90]

417.575 is active with searchers checking mine shafts. They mentioned mine teams from L.A. County and San Bernardino County. Currently searching the Rosa Peru mine, wherever that is. I haven't confirmed whether this is a BLM freq or Joshua Tree NP freq.

A couple of days ago I saw in the local news that there was a search going in the Yucca Valley area on for a missing 29 Palms teenager. Wondering if this is that search.

<>< Mike
Monitoring from western Riverside County

SBC uses the Motorola network now. This must be a mutual aid UHF channel.

[retiredFD07]

Are you using and outside antenna? I'm not hearing anything in Hemet, but don't have an roof mounted antenna yet.

Yes, I'm using a roof mounted antenna. If you're in Hemet, the San Jacinto Mountains are probably blocking your signal. From Riverside I'm practically line-of-sight through the Banning Pass to Joshua Tree.

RE SBC and the Motorola network: The reference was about the SBC search team. I wasn't hearing the actual search team, just what I now believe is BLM on the UHF. They seem to be co-ordinating everything.

<>< Mike

[Mike_G_D]

I think you're getting bit by your radio's internal issues again! Try looking at 460.375MHz which is a UHF CHP frequency (according to the RR db). I think you will find the real signal on that frequency.

Look over my math in this thread:http://www.scanriverside.com/forums/vie ... f=21&t=763. It works out.

-Mike

[cvrules90]

So that was probably an interop frequency used to coordinate big things like this.

[Mike_G_D]

Mike (retiredFD07) - I created an Excel spreadsheet for my own use to try and analyze the GRE internal superheterodyne frequency plan and potential artifacts like what you are experiencing. It's not intended for general use and has a lot of extraneous information - basically just me "dinking around with the numbers". However, I did make a simplified and color coded outline of the main issue you seem to be facing on the first sheet in the workbook,

Just put in the frequency you are tuned to (outlined in red and shaded in yellow) on the left side as indicated. Then read out the likely interferer (actual signal being received) on the left also highlighted in red and shaded in yellow. Ignore everything else.

It might help you in the future when looking through the 400MHz band. Be aware it may not always apply on all bands and only represents one form of undesired reception issue - there may be (are) many others which I have not outlined/analyzed in the spreadsheet. But it might help for a brief and easy first stage "sanity check".

I'll attach my Excel spreadsheet to this post. If you don't have Microsoft Excel, you might be able to use compatible alternatives like OpenOffice Calc but I can't guarantee the proper format, etc.

-Mike

[brandon]

I think 417.575 is one of the UHF links. It's been a while since I last heard it.

Old post from 2008

From my notes about 417.575 (last year)
Users discussing a campground and info about lost hikers; "San Bernardino North Entrance". Ref Oynx Peak and Bell. User called this freq "Zone"
Last week I monitored this all day and did not hear a peep. Either it moved as Exsmokey said, offline or the signal isn't reaching my location anymore.
I have also seen 417.575 listed as a link for 166.375 and the Mojave Natural Preserve. Hearing "North entrance" would make me think its some type of park.

http://forums.radioreference.com/califo ... ee-np.html

[Mike_G_D]

Brandon,

It's possible, certainly, but given the OP's previous issue as noted in the earlier thread regarding what he heard on 417.8MHz it raised a red flag in my mind and I ran the numbers; a strong signal on 460.375MHz WILL come through on 417.575Mhz on his scanner with his setup, therefore it would be best to check 460.375MHz when he is hearing something on 417.575MHz just to make sure what he is really hearing is really on that frequency fundamentally!

It may or may not be fundamentally on 417.575MHz but, given the data and knowledge we now possess concerning what his receive setup is susceptible to in terms of "false" signals, it would be prudent (and easy) to verify first.

-Mike