USER comment about Roomcap                                
  from Canary Islands                             

                                                                   3rd July 2010                                                                                                                                                                        


Fred, EA8AYT from Gran Canaria sent me the following mail:
(Translated from German)
---------------------------------------------------------------------------

Hello Felix,

first, I would like to thank you for your instrucions!

Furthermore, I tell you, how my present construction of the Roomcap looks like:

The radiator consists of a aluminium tube, 60cm long and 5 cm diameter and a PVC connection,
mounted on top of a PVC tube of 50mm length.

The feed is adjusted on 7 Mhz at 1:1, and the SWR remains at nearly 1:1 when changing  to
the higher bands; at 100 W not more then 1W reflexion is seen.

The frequency adjustment is done by the gear motor which is located in the lower part
of the PVC tube.


Practical experience:

I like to make QSOs on 40m in the afternoon mit Europe and the other stations on
Canary Island
s.
For example, if we are QRV in a group, EA8ADD with a 30m high dipole and 1 KW
receives S9+20 from north Spain (abt 2000 Km) and I receive with my 60cm long antenna
mostly S9.

Nobody likes to beleave, that my antenna is only 60cm long.
That's the result on large distance.
Very different are the comparisons during the QSO to the other canary islands, here the
signal difference is much larger.
Mostly, the Roomcap is around 3 to 4 S points weaker.
This shows, that in the near distance range (abt. 100 to 150 Km) the required high angle
radiation is missing, and the low angle radiation of the antenna provides a stronger
signal at large distance.

However, I can tilt my antenna into horizontal position, and and then the signal in
the neighbour islands is nearly identiacal to that of the fixed stations with their vertical
or dipole antennas.

On 40m DX I had a number of very good results, including VK and ZL.
On the other bands 10, 14, 18, and 21 Mhz I mostly obtain immediate answers
when calling in pile-ups.

On the two photos you can see my previous version, mounted on the trunk of my car.
That was very convenient to drive into the garage without to remove the antenna.
The performance was about the same, as mounted on the roof.
Unfortunately, I had to remove this one, as the police gave me a fee of 150 Euros,
as the antenna would endanger the traffic.
On top of the car there is no problem.


73s Fred EA8AYT
---------------------------------------------------------------------------------------------------------------------------
  
When asking Fred, if I may publish his letter, he wrote me on July 1st 2010:
-------------------------------------------------------------------------------------------------------------------------

The insolent rubbish written in the different mailboxes and discussion groups
nerves me since a long time!
For me the concept of the Roomcap is clear, and I know why it "works".

The results speak for themselves, and as I am nearly daily mobile qrv, your critics
can hear me, and even have a QSO with me.
I am frequently on 14313 in the German /mm net, working from the car, also in
Winlink and Sailmail, and also in CW on 7, 10, and 14 Mhz, and can only say,
that each of my CQs or calls is anwered promptly.

The efficiency of the antenna can be showed easily.
I still have installed a whip, 2 or 3 m long with an automatic tuner, and can switch
from one antenna to the other with a coax switch.
All comparisons show an advantage of the Roomcap, mostly between 2 to 3 S points.
 
The neon bulb test shows also clearly which antenna radiates stronger.
With the whip the bulb burns at a distance to 0.5 meter. With the Roomcap, depending
on the band, up to 2 meters.
This shows the difference very impressively!

I have no fix installation of the Roomcap.
But I have examined with many differnt lengths, diameters and frequencies, and
finally arrived at the 60cm version.

Yes Felix, maybe we can have together a QSO when propagation allows.
If you want to perform a new test, you can call me any time, maybe we can speak
in Skype, as I can activate the Internet in the car, using my handy as router.

73s Fred
   
---------------------------------------------------------------------------------------------------------------

Here the antenna of EA8AYT (today on the roof of the car):


 

back