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New Rucksack Antenna


Bought one of these new rucksack antennas last week curtesy of Sotabeams, http://www.sotabeams.co.uk/RSS.htm

On receipt of this antenna, bearing in mind I have only used it in the shack,I’am pleasently suprised with the excellent reports I have had locally using the antenna and the VX-170. An inexpensive 1/2 wave, portable, lightweight antenna, 2m of RG58 coax terminating in a BNC female plug. I hope to use this set-up on future activations. In the instructions though, it makes mention to operating while pedestrian mobile with the antenna, on summit activating keeping the same set-up assembled in the rucksack, fair comment. However, mention is also made to operating by slipping the open end of the pvc tubing over the end of an up-turned walking pole to give more elevation, excellent idea. In that case I would have expected the pvc pipe to have a plug inserted in the open end to accommodate a good fitting walking pole (Leki). Further, a collar fitted to the pipe and guying ropes plus pegs as issued with the WASP Special or similar.Perhaps the one bought is the prototype.
Anyone else thought along the same lines or a homebrew alternative?



I’m very impressed with the results (ie incoming reports and sensitivity) of mine. I use mine exclusively for pedestian operation, and still carry the SOTA Beam and WASP for setting up, guying etc on a summit. I can see that I will only set the SB3 up horizontal on summits from now on, while all the 2m FM work will be done on arrival or just before departure with the rucksack on my back.



In reply to M3EDX:

I used the RSS on my last trip to Helvellyn and found it outstanding compared to the usual RD. I carried out comparisons between the VX170 with the RSS and the FT60E and the RD and the difference was excellant. In the situation I was in on Saturday, the erection of the SB3 or HF was virtually impossible due to the severity of the winds but I was able to carry out 17 ‘easy’ QSO’s without even removing the rucsac from my back. I will still carry the SB3 and operate HF but for 2m FM there is only one aerial for me.

With regard to its use on an inverted treking pole - yes there could be a plug inserted but that limits its use to Leki as in the case of the WASP. However, I dont think it necessarily needs any other form of support other than the rucsac. Use it on arrival or on departure then concentrate on 2m SSB and HF.

73 Glyn


Hi Tom
Thanks for your reply. The operation you make mention too is exactly how I also intent to operate using the VX-170 and the RSS on FM and the SB3/WASP Special with FT-817 on SSB. I think this operational set-up is ideal to get the most out of an activation minus the HF element. SOTAbeams have to be congratulated in my opinion on the portable equipment they make available for participation in the SOTA scheme…



In reply to GM4CFS:

Hi Glyn
Thanks also for your reply. Your comparisons are noted. Again this RSS set-up caters for bad WX where the SB3 would not prove practical to use.
I further take your point in using the RSS as intended within the rucksack, no problem there, but it could be used in the same way as the WASP Special if fitted with a type of inner plug at the open end to accommodate a Leki or other walking pole, this would provide choice of set-up. Of course a collar of some description plus guys and pegs would be required as an addition. It would not suprised me if this is included as an addition by SOTAbeams at a future date with a slight increase to the original price tag.



In reply to M3EDX:

Anyone else thought along the same lines or a homebrew alternative?

Yes, it is similar to my 1/2 wave dipole from OD 8 mm aluminium tube



A U-bolt is used for fixing it on Leki pole. For the fixing on rucksac I use 4 mm rope. You should be able to mount it on the rucksac on top of rain cover if needed with the same rope. I was thinking of making the dipole inside PVC tube, but the tube feels too heavy on my hand. Need to think something else. I use only 2.5 W during walkup for the APRS packets since there is no guarantee of SWR during movement. The packets have always gone through from the hill tops here, but during walking the data loss is 80 - 90 %. One down point is that you are exposing yourself to the RF field of antenna, so I do not like to transmit often. The tracker is set to transmit every 10 minutes. Note that you could improve the directivity of the horizontal dipole with a sheet of aluminium foil or similar, but then somebody has the keep the sheet in place while you are talking :slight_smile:

73, Jaakko OH7BF/F5VGL


In reply to F5VGL:

Hi Jaakko

Many thanks for your reply.

Apologies to all. I have just been sitting in the shack pondering the question raised in this thread and wondered whether the existing WASP Special would accommodate the RSS and guess what,it does… I now feel stupid!

On inserting the bottom portion of the RSS through the eyelets on the WASP it supports the RSS below the coil adequately allowing the same type of operation as used in conjunction with the SB3 & Leki pole…

Going a stage further, in this configuration, minus the Leki pole of course, the RSS and WASP can be straped to the outside of the rucksack while pedestrian mobile allowing more room in the rucksack if required.

…oh well we live and learn!