Sierra Echo PMR Repeater Group

Licence free two-way radio services that now includes both FM and digital channels. Discuss models, modifications and other similar worldwide standards such as FRS and GMRS.
Post Reply
MikeSE9
Regular
Regular
Posts: 93
Joined: 15 Nov 2008, 09:38

Sierra Echo PMR Repeater Group

Post by MikeSE9 »

Hi, some of you in the South east might be interested in this

https://www.facebook.com/Sierra-Echo-PM ... 0/?fref=ts
M3VBS
Radio Addict
Radio Addict
Posts: 680
Joined: 11 Feb 2008, 16:15

Re: Sierra Echo PMR Repeater Group

Post by M3VBS »

Interesting thanks. Don't do facebook so I can't see behind the initial page - any idea if ctcss is used and what tone
paulears
Top Poster
Top Poster
Posts: 1088
Joined: 10 Jun 2007, 22:41
Call Sign: G4RMT
Location: North East Suffolk
Contact:

Re: Sierra Echo PMR Repeater Group

Post by paulears »

I don't get it at all - it doesn't run much power, so unless it's perched on the top of a mountain or hanging from a balloon - does it do very much? The frequencies are so close that desense means big and heavy cavities, or aerial spaced a very long way apart - have I totally missed the point? Probably, knowing me!
User avatar
radiosification
Top Poster
Top Poster
Posts: 2495
Joined: 27 Dec 2010, 23:52
Location: London
Contact:

Re: Sierra Echo PMR Repeater Group

Post by radiosification »

Interesting. They're also using 446.9875mhz as the repeater's RX channel so you'll need a huge antenna and your transmissions might go all the way around the world because it's such a low frequency. Don't know why they didn't choose a frequency in the UHF band or maybe on the VHF band would have been better then they could have had a crossband repeater.
If you're interested in digital voice, check out my YouTube channel:
http://www.youtube.com/radiosification
paulears
Top Poster
Top Poster
Posts: 1088
Joined: 10 Jun 2007, 22:41
Call Sign: G4RMT
Location: North East Suffolk
Contact:

Re: Sierra Echo PMR Repeater Group

Post by paulears »

Eh? 446.9875MHz is UHF - confused.
User avatar
mercury888
Regular
Regular
Posts: 51
Joined: 04 Aug 2016, 12:22
Call Sign: M0RVB
Location: Leeds, West Yorkshire
Contact:

Re: Sierra Echo PMR Repeater Group

Post by mercury888 »

paulears wrote:Eh? 446.9875MHz is UHF - confused.
Indeed, but they quote mhz, milli-hertz! With a small 'h' at that!
CB: President Grant II (1980's handle: Bootstrap; now 26TM868)
ADS-B: FR24 T-EGNM-63
Yaseu FT450D; Signal R535; W-SDRX1 + Gnu Radio and CubicSDR
Baofeng UV5R; TYT MD380; Trio TR-9130
paulears
Top Poster
Top Poster
Posts: 1088
Joined: 10 Jun 2007, 22:41
Call Sign: G4RMT
Location: North East Suffolk
Contact:

Re: Sierra Echo PMR Repeater Group

Post by paulears »

Aha! A joke. I get it! Wish I didn't now.
User avatar
Admiral
Legend
Legend
Posts: 10108
Joined: 08 Mar 2011, 21:20
Call Sign: 26TM157
Location: MK-UK

Re: Sierra Echo PMR Repeater Group

Post by Admiral »

More power to your elbow mate, but I think you guys will be making yourself a sitting duck if someone get's the hump.
Winner of the 2017 IBTL 'Summer Sizzler' competition
User avatar
bigbloke
Top Poster
Top Poster
Posts: 1449
Joined: 25 Aug 2008, 17:53
Location: Nominally Newport (South Wales) but potentially "anywhere"
Contact:

Re: Sierra Echo PMR Repeater Group

Post by bigbloke »

I notice their FB page says 446.9875 is an old SRBR channel......it isnt !

hope they're not near the coast as its rather close to a navy POLYCON frequency!

Regards

BB
User avatar
Admiral
Legend
Legend
Posts: 10108
Joined: 08 Mar 2011, 21:20
Call Sign: 26TM157
Location: MK-UK

Re: Sierra Echo PMR Repeater Group

Post by Admiral »

I notice their FB page has no updates for 6 weeks.
Winner of the 2017 IBTL 'Summer Sizzler' competition
MikeSE9
Regular
Regular
Posts: 93
Joined: 15 Nov 2008, 09:38

Re: Sierra Echo PMR Repeater Group

Post by MikeSE9 »

What are the chances of a 0.89375MHz split working with out cavities, or a big separation between antennas on Baofeng Radios?
User avatar
Admiral
Legend
Legend
Posts: 10108
Joined: 08 Mar 2011, 21:20
Call Sign: 26TM157
Location: MK-UK

Re: Sierra Echo PMR Repeater Group

Post by Admiral »

MikeSE9 wrote:What are the chances of a 0.89375MHz split working with out cavities, or a big separation between antennas on Baofeng Radios?
Slim
Winner of the 2017 IBTL 'Summer Sizzler' competition
AlfieDivine1
Regular
Regular
Posts: 48
Joined: 30 Aug 2017, 11:34
Call Sign: 26CT2369
Location: Folkestone
Contact:

Re: Sierra Echo PMR Repeater Group

Post by AlfieDivine1 »

Calling PMR CH 8 each Sunday & Mondays throughout the day,
located in folkestone South East England.
Steve B
Regular
Regular
Posts: 69
Joined: 30 Apr 2017, 03:53
Location: Europe ;)

Re: Sierra Echo PMR Repeater Group

Post by Steve B »

MikeSE9 wrote: 01 Oct 2016, 17:17 What are the chances of a 0.89375MHz split working with out cavities, or a big separation between antennas on Baofeng Radios?
is that the terminology? cavities? referring to how the TX output signal of the repeater messes up with the AGC of the reciever?
30-Tango-Mike-003
Good Christian Boys: Midland G7 XTR "Street-Legal" PMR 3-watter - Kenwood UBZ-LJ8 PMR446 - Intek FM548SX (With Homogolation boys 8) )
Naughty Boys: Philips 25W FM1100 UHF w/PA4DEN - Baofeng UV5RA, Superstar 360FM (My good one!) w/ CTE 747 100W Amp
Freddie
Regular
Regular
Posts: 39
Joined: 09 May 2015, 13:19

Re: Sierra Echo PMR Repeater Group

Post by Freddie »

No ;)

Most repeater systems use a duplexer to allow TX and RX to share an antenna without interfering. I'll leave it for someone cleverer than me to describe the physics of HOW they work, but they use a series of metal "cans" or cavities to do what they do.

The phenomenon you describe (which cavities or other filtering will hopefully minimise) is just called de-sensing I believe.
Post Reply