DMR MD380 Reception Boost - Help.

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DMR MD380 Reception Boost - Help.

Postby iScottybotty » Mon Dec 18, 2017 1:44 pm

Hi all,

Just looking for some advice from the more experienced members in the use of DMR than myself.

So the MD380 is set-up correctly and using the MD380tools from Travis Godspeed, however on one particular frequency the reception isn’t all that good, unless that is I hold my handheld with my arm in the air in one particular spot at home.

When the Group Calls are coming through, I notice that unless my reception is on three bars, I’ll miss every modulation so my question is, can anyone recommend a signal booster for DMR just so I can get a few more signal bars to pick up all the modulations easier than what I’m doing now. Currently the signal strength is a solid two bars/ flashing onto three but I need a solid three or four or even better, full bars.

I know aerial questions often come with a reply of, “how long is a piece of string” but even so, if someone can recommend a specific type of aerial for the 380 that would be awesome too. The frequency I want is specifically in the 443mhz band.

As ever, any help and or advice would be appreciated.

Thanks all.
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Re: DMR MD380 Reception Boost - Help.

Postby Metradio » Mon Dec 18, 2017 1:53 pm

An outside aerial would work well..

Mike
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Re: DMR MD380 Reception Boost - Help.

Postby iScottybotty » Mon Dec 18, 2017 2:08 pm

Hi Mike,

Yes, indeed. Would you be able to recommend one at all? I’m confused now, doesn’t take much, but do I need a specific type for DMR or am I overthinking where a normal 400-512mhz aerial would do?

I used to have a little black box, took a PP3 battery and would have a BNC connector each end. I think it was an amplifier of some type. If I brought that, with the bnc- md380 adapter to connect to the radio, would that be of any benefit?

The signal is literally being missed by one bar. Thanks Mike.
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Re: DMR MD380 Reception Boost - Help.

Postby m0lsx » Mon Dec 18, 2017 3:03 pm

If all you have to do is hold the antenna higher in the air, then a simple nomad from Spectrum will solve that.

Image

http://www.spectrumcomms.co.uk/Aerials.htm

NOMAD WIDEBAND PORTABLE SCANNER AERIAL 25-500MHz. The aerial element is made from 300 Ohm feeder configured like a Slim Jim, with modified stub matching to give greater operational bandwidth. It is intended to be portable but can be used as a permanent aerial in places where conventional wire aerials cannot be used. The overall length is 1.4metres and folds down to just 25cm (10"). It is fitted with 4m of 50 Ohm coax cable with a BNC male connector as standard, but can be supplied with PL259. For better reception of Air-band, 2m Amateur band or Marine-band use the Slim-G detailed above. Price £22.00 UK


That £22 includes postage.

I use a home made dual band version of this for portable operation. Mine does not have the plastic tube & rolls up & fits in my pocket. My daughter also made & used one in her bedroom when she was first licensed.
They can hang from a tree, in a corner, in a window, fit inside or outside of a tube or tape to a pole for permanent out door use. They can hang in a loft or as my daughter did tape to a cabin bed legs.
When operating from a school in the City centre I use to get good reports from mobile stations around 10 miles away on 2 meters with the antenna hung off a blind in a very tall window.
For JOTA stations I use my roll up taped to a 10 meter roach pole.
At £22 it may not outperform a discone or colinear outdoor antenna at 50 feet. But you have nothing else to buy & you need rather large pockets to fit a discone, a pole, a wall bracket & several meters of RG-213 into.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via http://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
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Re: DMR MD380 Reception Boost - Help.

Postby Metradio » Mon Dec 18, 2017 5:48 pm

iScottybotty wrote:Hi Mike,
Yes, indeed. Would you be able to recommend one at all? I’m confused now, doesn’t take much, but do I need a specific type for DMR or am I overthinking where a normal 400-512mhz aerial would do?

That Nomad antenna looks good..
You do not need any specific antenna type for DMR, no more than you need a special aerial for Freeview TV..
I used to have a little black box, took a PP3 battery and would have a BNC connector each end. I think it was an amplifier of some type. If I brought that, with the bnc- md380 adapter to connect to the radio, would that be of any benefit?

Think you will find the antenna upgrade will be enough..

Mike
Connect Systems CS750 and CS800, Hytera PD-365, Motorola DP4600.
Raspberry Pi 2 and DV4Mini HotSpot.
AOR AR-DV1 Digital Voice Receiver / eSPY on ARD.
WS1088 / TRX-1 / Whistler Q /UBCD3600XLT / WTR Browser.
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Re: DMR MD380 Reception Boost - Help.

Postby iScottybotty » Mon Dec 18, 2017 5:54 pm

Hi M0LSX, hi Mike.

Thank you for the above. Yes, I’ve checked out the Nomad antennas and spoke to them directly, they have suggested a similar type but with a built in pre-amplifier? It’s not at the price you quoted, almost double but I’m more confident in that it’s likely going to work now I’ve had a positive response re a similar item from yourself.

In the meantime I’ve been out and brought a MRW-210SM, I got it for £10 so I’ll give it a try and see where I am.

Thank you to all thus far, of course if anyone else has something to recommend, please post as I’ll check regularly.
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Re: DMR MD380 Reception Boost - Help.

Postby m0lsx » Mon Dec 18, 2017 6:50 pm

iScottybotty wrote: In the meantime I’ve been out and brought a MRW-210SM, I got it for £10 so I’ll give it a try and see where I am.


Good luck with that, it's a mooraker. But if works, it's a reasonable buy at £10.
I find those longer antennas are good at increasing signal strength on a weak signal.
Buy a database from Kimmy JS19 via http://ukscanningdirectory.co.uk/
Or do Google search of this forum via http://www.google.com/cse/home?cx=partner-pub-6291336405621919:2662881632
73 De Alan (M0LSX.)
http://www.qrz.com/db/M0LSX"
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Re: DMR MD380 Reception Boost - Help.

Postby warlock01 » Tue Dec 19, 2017 12:05 pm

hi, just a thought, and i am sure other people will give you there ideas as well ,my antenna situation is poor due the fact i am not allowed to put nothing fancy. i have have a metal roof so i use mag mounted mobile antennas for different frequencys and they seem to work quite well. but the preamps i have used for a few years now are the jim m75, it has variable gain control and three switchable band filters. they are about £80.00 ish , which is a lot of money but they realy make the difference..i am situated about 40 miles west of london heathrow, and the 455.000 uhf air traffic relay transmissions are very good. regards
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Re: DMR MD380 Reception Boost - Help.

Postby iScottybotty » Tue Dec 19, 2017 5:40 pm

Hi warlock01,

Thanks for the comments and referral. I’ll check the pre-amp out as where I live, the “apartment block, if you like” is owned by a Management Company and I’m sure they’d have something to say if I put something on the roof.

That said, the aerial I brought yesterday seems to be working well and I’m glad to say is easily picking up all the comms I was struggling with before. But, typical me, now I know there are more, lots more comms I can pick up in a similar way to that as before with the old aerial, I am considering a roof aerial even though. Oh where does it end!
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Re: DMR MD380 Reception Boost - Help.

Postby warlock01 » Tue Dec 19, 2017 8:05 pm

hi, ok on comments, i am realy to far away for any dmr decodable comms in the 443.000 area, but i can rx a lot of analouge comms from what i think is heathrow .not sure where you are getting the info from to program your tyt. but a lot people including myself use a program called dsd+ to find talk/groups colour codes ect then transfer that info to the radio. the other option is to buy a dmr receiver , but they tend to be a lot of money. good luck,
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