Extending Range

Post Reply
VK2MJM
Posts: 5
Joined: Sun Dec 25, 2016 7:06 pm

Extending Range

Post by VK2MJM » Sun Dec 25, 2016 7:15 pm

Hi,


I always wonder why there are options with very low power, and few options for moderate power, say 5Watts, when it come to standalone hotspots. Clearly OpenSpot is a winner, particularly when it comes to portability, functionality and value. However, how can low power be converted to higher power, while maintaining relative portability. I travel a lot to areas with no access to repeater sights, but would really love to be able to extend the range of the OpenSpot to make it more satisfying and useful. Has anyone tried a cross band repeater/radio, or other means.

I haven't bought one yet, but am considering my options.

Also, do ports have to be forwarded, or can it be used with the Ethernet cable, say in a hotel room, without having to change settings on a router?


Thanks

gabriele
Posts: 17
Joined: Mon Dec 12, 2016 7:47 am

Re: Extending Range

Post by gabriele » Mon Dec 26, 2016 11:21 am

HI
-to extend the transmitting range you could use a power amplifier specific for digital modes with openSpot connected to home internet and to an external antenna.
The PA must to be one of low latency type (pin-diodes switching, no relais), and suitable for the driving power of openSpot (20 mW max), like model P8X (8-10 w.out) of DF2FQ that works very fine to me.
-in this way you will need to increase also the receiving range of openSpot on an external antenna, and you must have of course an adeguate transmitting system to operate. Performances depend the same way of analog repeaters.
For a mobile use everywhere is available internet mobile, openSpot will do a great job linked to your phone turned to wifi router, and so you will become completely independent from public internet, wifi or ethernet, and power supply also. To do the job you will need to add to the list a power bank and a bridge ethernet-to wifi. This is the typical use of openSpot I like, and the low output power is the right for this purpose.
73 Gabriele, I4JXE

dmlad4uu
Posts: 19
Joined: Thu May 12, 2016 12:33 pm

Re: Extending Range

Post by dmlad4uu » Mon Dec 26, 2016 11:44 am

I also have 2 openspots. Both with the P8X amp on them. I am able to hear my hotspots for 6 - 7 miles using the amps. 1/4 of a mile without the amps/ Outdoor antennas. The amp work great but the receive sensitivity on the Hotspots is not so good. The Openspots can only ear me form abt 1 1/2 miles away. Limiting there use for an extended home Hotspot. Antenna are up 30 and 40 ft.

User avatar
g8koe
Posts: 146
Joined: Sun Sep 04, 2016 8:33 pm

Re: Extending Range

Post by g8koe » Mon Dec 26, 2016 12:59 pm

Hi,
Why would you take an openSPOT which has a balanced TX & RX designed for local use and unbalance the system with a PA?
The receivers on all hotspots are basic and will suffer from cross-mod desense etc from strong RF signals.
Why do commercial repeaters cost £1500?
73's
Martin
G8KOE

VK2MJM
Posts: 5
Joined: Sun Dec 25, 2016 7:06 pm

Re: Extending Range

Post by VK2MJM » Mon Dec 26, 2016 7:22 pm

Hi Martin,


Thank you for your reply.

I understand that there could be some desense from over powering? If so, then what solutions are there for someone who needs more power/range while maintaining portability?


Jeremy
VK2MJM

User avatar
g8koe
Posts: 146
Joined: Sun Sep 04, 2016 8:33 pm

Re: Extending Range

Post by g8koe » Mon Dec 26, 2016 8:06 pm

Hi,
I use my operSPOT linked via a small router to my mobile phone.
This is a small setup and totally mobile can be used in car or backpack.
A go anywhere solution.
Alternatively MMDVM software and modem connected to suitable transceiver such as FTM400.
I have this high power setup but prefer to use my openSPOT system.
73's
Martin
G8KOE

gabriele
Posts: 17
Joined: Mon Dec 12, 2016 7:47 am

Re: Extending Range

Post by gabriele » Mon Dec 26, 2016 8:39 pm

You will not have any noticeable desense using a PA like P8X, if the system cables-antenna has no mismatch. By the way the insertion loss is less than 1dB.
Reading the rx performance reported in the manual of openSpot

<Receiver sensitivity:

Gaussian 2FSK: -114 dBm @ 9.6 kbps
Raised Cosine 4FSK: -109 dBm @ 9.6 kbps>

that are not bad at all, I assumed that few watts more on tx and an external antenna could allow better performance with my cheap MD380 here around the qth, since with openSpot and his antenna the coverage is limited, at wifi-device level.
Yes the tx/rx performances are increased but in an unbalanced way, rx looking a bit too deaf in my tests on field according to the specs above.
So, in my opinion, is definitely not the way to follow for your purpose, remaining only the use of DMR mobile where internet is available.
Best regards.
73 de Gabriele, I4JXE

bx2aek
Posts: 36
Joined: Sat Dec 17, 2016 1:09 pm
Location: Taipei, Taiwan

Re: Extending Range

Post by bx2aek » Tue Dec 27, 2016 10:24 am

Hi I heard P8X is helpful to extend the range of Openspot and compatible to it, any web store we can make an international order? Thanks

Kim
BX2AEK
Taiwan
Kim Liao
BX2AEK

Taipei, Taiwan
bx2aek@gmail.com

DL7DW
Posts: 13
Joined: Sat Oct 29, 2016 8:47 am

Re: Extending Range

Post by DL7DW » Tue Dec 27, 2016 11:30 am


K7REX-Dan
Posts: 26
Joined: Fri Aug 26, 2016 3:17 am

Re: Extending Range

Post by K7REX-Dan » Tue Jan 10, 2017 9:39 pm

You can find out more details about the P8X UHF-Power Amplifier and other products at http://www.df2fq.de -- You can also send an email to Holger Eckardt at: [url]df2fq@darc.de[/url]

Holger also has English language manuals for the P8X that he'll send you...

Post Reply