RoomCap Antenna = Capacitive Antenna    
Felix Meyer             
upd: 4Oct13,12Oct13,5Feb14, 21Jun14, 23jun14, 26Nov14, 13Feb2015, 30Sep15 , 23-Febr-2017 , 6.April 2021                    

Clicke hier für die deutsche Version

A new, revolutionary idea allows the construction of small HF antennas,
which provide the same efficiency as large antennas.
Example: tested by Military  +  SUPER DX results on 80m + 160m DX Antenna <<<  Big success !

Public demonstration of the antenna was here: 
- 27th. October 2007 in ZOFINGEN  -   here a picture     and one more
 at the  "Surplus Party", the largest HAM Radio fair in Switzerland  
- 30 Sept. 2015 in Lörrach see here 

If you want to see it in operation: Ask and arrange a date (phone or e-mail to me).

      Technical specifications of the new HF ANTENNA: 
The name of the antenna is ‘RoomCap Antenna’(from Room Capacity)
      and is for use on the 10-15-20-40-80 m (+WARC) bands.
      (UPDATE 20.8.06)  and for 160 m (radiator tube 75 mm and 3 m long).
      The radiator of the antenna consists of an element in the form of a tube
      of 5cm diameter and a length between 50 to 170 cm, depending on the
      frequency, with an additional 25 cm length (approximately) for the connection
      and mechanical mounting space.
      Normalwise the radiator is 50 cm to 100 cm above the car or house roof.
      Update 28.7. 2013:
      The antenna of the 2nd generation has no longer the thick tube.
      Instead of the tube,
a light wire grid of 1m x 1m is used. This brings
      even more efficiency, and
the antenna is less visible.
      This radiator serves for all bands from 10m to 80m!
      A modified feeding system allowed to include the bands 10-12-15-17-20 with an
      SWR of 1:1 and a very large bandwidth.
      On 20m the bandwidth is more then 800 KHz, on 15m more than 4 MHz!
      >>> The 160m antenna is longer, use a 3m long, and 1m wide radiator (grid)!

      The feed impedance of the antenna is 50 Ohms, and it does not need a  tuner
      to reach an SWR better than 1 : 1.1 on all bands.
      With the remote frequency adjustement RFA (inside the tube), any frequency of
      the band  can be set to SWR 1.0 in a few seconds.
      The radiation pattern in the H-Plane is a circle and in the E-Plane has a broad
      minimum upward, while the radiating beam is flat to the side with
      maximum radiation angle between 15 to 25 degrees  (depending on
      frequency and height above ground) = low angle radiating antenna.
      Polarisation of the antenna is vertical.
      This antenna can be built as a monoband antenna, or as a multi band antenna.

      Area of application:
       1. Mobile antenna with exceptional efficiency which barely can be surpassed.
       2. Fix or portable  antenna, as antenna does not need a support to hang up wires
           in the air, and works at low height with highest efficiency.  Picture

      Transmit power: The antenna is designed for 200 W PEP.
      By observing the special hints, the antenna can be built for 1 KW PEP.
      The efficiency of the antenna is extremely good in comparison to
      other antenna types. The comparisons can be found in the  following test reports. 

It is not the intention, to replace other, large antennas. This antenna works by using
small dimensions as a very efficient antenna,
without the need of supporting poles,
what, by using traditional antenna design, is not possible.
Read the explanation June 29th 2006 (towards end of this page).
And important text:  Antennas and Physics   
>>>  Introduction to Roomcap  +  Theory

        >>>  Information to order the  construction guide:   HERE   <<< (click)

                                           Last update of construction guide = 9th Jan 2017 
  Read here

The following test report is no claim. This is simply a description of the experiences
and the contacts made with this antenna.
All data can be verified, as date, callsigns, and frequencies of contacts are indicated.
Everybody is invited to participate personally in the tests here.

Here is the picture of the new HB9ABX Antenna for 40 m, year 2005:
      2005 vers
       Many thanks to Samy, HB9BPP for the picture!

       And here the Roomcap 2nd Gen (10 to 80m) year 2013
      2013 version  

  The antenna serves as excellent Mobile Antenna, but also as Home Station Antenna!

  The antenna is a band antenna, which I would like to call "capacitive sky radiator",
   therefore the name  RoomCap Antenna.

  The time is over, where one needs a big antenna to produce a big signal.
  This small antenna equals the performance of the large GPs as Cushcraft and Butternut!


in chronological sequence

State: 7th June 2005  (LINK added 15th December 2005)

Fantastic results obtained with new small antenna.
The last days I was testing my recently developed antenna on 40m, in mobile use.

The tests were performed by comparing signals with the following antennas:

FD-3, G5RV, 4-BTV Groundplane and Butternut HF-6V (= 6-Band Vertical).
All stations were operating with 80 to 100 W in the local area of 12 km to my mobile station.
I was using the TS-50 with max. 100W operating on the car battery.

The comparing tests were always in the same QSO with frequent changeover between the
comparing station and the mobile station.

In total, 38 Test QSOs were conducted, where the mobile station received a better
signal report in 32 QSOs from the Remote Station, in 4 QSOs the signals were equal, and
in 2 QSOs the Comparing Station was stronger.

The Remote Stations were in Germany (Stuttgart to north coast), France, Italy,
Austria, Isle of Corsica, UK, and the Netherlands.

Mostly, the mobile station received a signal report 1 to 2 S-points stronger than
the comparing station, and some reports were 20 dB stronger than the comparing station.

The feet of the mobile antenna was on the car, 1.5 m above ground, and the length of the
antenna was 1.5 m.

Location of mobile station: Peripheric parking place in the city of Basle.

The Butternut HF-6V comparing station was on top of a free standing 30 m high building,
and also here the resulting reports were 2 times 1 S-point better and once
1 S-point less for the mobile station.

Overall, a nearly incredible good result.

One thing I can reveal here:
This is not a Microvert and no EH-Antenna. Here is  LINK to EH-ANTENNA
I call it a "capacitive sky radiator".

The antenna wil be described after completion of the full test series.

State: 14th. June 2005 : 20m Tests
Since a few days I am testing on 20m.
Also in comparison QSOs wit nearby local stations.
The results look very similar to the 40m results:
On July 10 at 12.30 h QSO with EA3EHC and IK7LQH,
3 further stations were qrv in Basel.
The only station heared in Spain and southern Italy was
my mobile station ...

On July 13 at 12.30h contact with EA3EHC
in Basel HB9PP with
GP (Diamond CP5), HB9TQL with Butternut HF-6V,
HB9TQN with Hustler 4-BTV GP, HB9DRJ with FD-3. There were bad conditions.
We received the following reports:

HB9PP 30
RoomCap 54

On July 14. I made a comparison with HB9BXS, who operated with
R7000 from Cushcraft on the roof of the building in a very good location.
I parked my car wit mobile antenna 100m distant from his house
and we had following QSOs with the following received reports:

GM7ASN 03 55
LA6FX 55 57
EA1TSR unreadable 57
4Z5NB/m 33 57
RD3AW 56-7 58

Overall: very exciting results.

State: 16th. June 2005: Measuring results

Measured on the new HB9ABX antenna (20m) = (Roomcap antenna)

For interested I was measuring today the new antenna.
The following SWR values have been noted:

(Measured on installed antenna on the car through 2 m coax cable)
on June 16th, 2005
  with recalibrated MFJ-269.

14.000   1.5
14.023   1.4
14.054   1.3
14.062   1.2
14.090   1.1
14.123   1.0
14.200   1.0
14.232   1.1
14.250   1.2
14.290   1.3
14.330   1.4
14.350   1.5

The SWR 1:2 bandwidth goes from 13.870 - 14.460
which corresponds to  590 Khz bandwidth.

The range of SWR 1.0 is adjustable in seconds to any
frequency within the 20m band.

Now I am leaving to HAM Radio Friedrichshafen and my next
reports will follow after the "HAM Radio".

Maybe we meet us in Friedrichshafen ?

State: 2nd. July, 2005

Antenna comparison 2nd July 2005
Band 7 MHz , 15.00h to 15.30h MESZ
QTH: Allschwil near Basel

Test antenna: New HB9ABX antenna (Roomcap) (1,5m radiator) on the roof of my car.
Comparison antenne: Cushcraft R7000 from HB9BXS.

Station HB9ABX: TS-50 on 12V, 100 Watt PEP
Station HB9BXS:  IC-756 Pro II, 100 Watt PEP

First we measured the R7000 and noted,
that the resonance for 40m was on 6.950.
We took down the antenna, shortened to top segment
until the resonance was in the center of the band with
an SWR of 1.0
The station was checked to verify, that 100 W output was reached.

The antenna is located on a family house at the border of the city
on a hill position with good view over the city of Basel
With car and mobile antenna I drove some 150 m aside
to be outside of the houses, and the test could begin.

During each QSO multiple switchovers between HB9ABX and
HB9BXS in order to allow the remote station to measure
the average signal strength difference.

Remote STN  rprt for HB9ABX  rprt for HB9BXS   QTH

GB2GDO              59                      57-59                     nr. Gatwick Airport
DL0MUE              59                      58-9                       Mühlberg/Elbe Brandenburg
DC6EG                 59                      58                          Bielefeld
PA2L                     59                      58                          Elburg Holland
OE5EPG/5            58                      57                          portable on the Traun
In all QSOs multiple short switchovers between ABX and BXS
and the comment was regularly, that ABX arrives mostly one  S-point
Then the test was terminated for this day.

State: 6th. July, 2005

6th.July 2005: Antenna test, new HB9ABX Antenna (Roomcap) on 40m, antenna on the ground
During all previous tests the antenna was installed on the car with
1.5 m distance between ground and antenna base.
Today the antenna was mounted directly at grond level for the following test.
The SWR was also at 1.0 .

Test station:  HB9ABX with TS-50, 100 W, 1.5 m long radiator.
Comparing station: HB9EBG with 100W and dipole 2 x 20m,
with 500 Ohm feeder line and antenna tuner between TX and feeder.
Location: Also in Basel.

Test time: 17.05 to 17.55 MESZ , listing the received signal reports
(= signal report at remote location).

Remote      HB9ABX   HB9EBG       QTH
DK9KS         58              59                 nr.Bonn
HB9MGY     59+20        59+20          Duggingen
DM3KXL     58              57-58           nr.Dresden
DH7GGF      57-59         57-59           Augsburg
HB9PLH       59+10       59+10           Schaffhausen
G0DML        57 QRM  unreadable   Manchester

Obtained comments:
Generally, the signal of  HB9EBG was about one S point stronger than HB9ABX,
also 3 to 6 db were given, while during the QSB, the signal of the test station reached
the same signal strength as the comparing station
Exception: Report from England, where HB9ABX was hearded with S7 with QRM
while HB9EBG was not readable.
Conclusion: Direct ground mounting provides less signal strength.

State: 8th.July 2005

Antenna comparison with Microvert MV-500: 8th. July 05

Today I could perform a Comparison between the new
antenna and the Microvert antenna on 40 m .
I was expecting long time to have this possibility,
as this antenna is mentioned many times as a very good
short antenna.
But, there is not "the Microvert", as there exist a wide
variation of different versions, described by the inventor,
At HB9MGY I found two variants for 40 m, the ordinary
slim version, and the improved version with the round plate
above the coil, called model MV-500 or Station antenna.
The coil is wound in a special manner for low capacity.
We used the improved MV-500 for our test.

Location: Duggingen, 12 Km south of Basel.
Time: 10.00 to 10.25 MESZ

Test station:            HB9ABX with TS-50, 100 W
Comparing station: HB9MGY with 100 W

The MV was located on the free terrace on the side
of the house, on a 1.5 m high support

and I parked my car abt. 20 m next to the house,
somewhat lower.
The location is to be considered as bad location for HF,
as Duggingen is down in a narrow valley.
We had contact with HB9ATX/EA3, located near
Palamos near to the coast in Spain.
We received the following reports:

HB9ABX = S4 to S5 with 100 percent readability.
HB9MGY = S1 to S2, signal was heared, but unable to understand.
                     The signal from HB9MGY increased by one S-point
                     after he switched to the longwire antenna.

Other stations listening in Basel noted a big difference between the
two stations.
Report from HB9BPP:
HB9ABX  = S9+5 dB
HB9MGY = S6 with Microvert
HB9MGY = S7 with longwire

Further tests will follow.

  State: 12th. July  2005

Today a Test was performed on 20 m as comparison with the
Cushcraft R7000 from HB9BXS.

Test station: HB9ABX, 100 W, 1.3 m long antenna on the car.
Comparing station: HB9BXS, 100 W, R7000 on top of the roof.
Distance between test and comparing station abt. 150 m.

Time: 16.05 to 1745 h MESZ, 14260 - 14290 KHz

Reports received from remote stations:

Remote      HB9ABX   HB9BXS    QTH

SM5HDJ    58              57               nr.Stockholm
G3GYE       55              54               Landsend
IS0HQJ      54              54               Sardinien (Insel)
2E1GOS     59+20        59               George UK
G0LHH      55              55               Birmingham
G6ZBV/m   57              57               nr.Birmingham
M3JUQ      57              56-7           N-London
G0GNE      57              56              Guildford
9A2KL/YU 59              58-9            nr.Belgrad
G8GIY       59              57               Mutlock
F/PA1EW  58-9           58-9            SuedFrankreich
4L4MM    57              57 ?            Georgien

During all QSOs several short changeovers between
ABX and BXS and requesting the remote station to measure
the signal difference, averaged in the QSB.
Hereby the difference was mostly 1/2 to 1 S point, in some
cases 2 S points stronger for HB9ABX. In no case the signal
of HB9ABX was weaker.

Is the new antenna a wonder ? >>>>>  Look here.

State: 13th. July 2005

Antenna comparison Microvert 40 m extended
On July 8th only a single QSO could be performed, comparing the Microvert
antenna. Therefore an extended comparison was planned for today.
The improved Microvert MV-500 was installed in a free test field close
to the new HB9ABX antenna, mounted on the car. Both antennas have the
same length and are installed at the same hight connected to the same
transceiver via a Coax Switch.
Both antennas indicated SWR 1.0 on the crossneedle instrument.
The test began at 12.20 MESZ and terminated at 14.45 MESZ, after
completeing 14 comparisons contacts
The results showed a clear picture, which indicated that the new HB9ABX
antenna received in most contacts 1 to 2 S points more (= 6 to 12 dB).
In the receive mode of the signals the same difference was noted.
The comment was generally: With HB9ABX antenna also in QRM good
readable, while with the MV nearly unreadable.
Here follows the received signal reports in S points:

Ant1 = Roomcap Ant,   Ant2 = Microvert, Modell MV-500 (DL7PE)

Remote     Ant1    Ant2      QTH

DF6OE        7          5          nr.Ingoldstadt
F5FCH         8          6         Blois
DC6NY        9          9         nr.Nürnberg
DJ4WJ         5          3-4     Neumark
DL5KUA/p  9+5dB  8        Stabehoch nr.Burg
I3/I6KYL     9           8         Bellano
DG4BZ        9           7         nr.Osnabrück
DK9HJ        5           3         North sea, coast
HB9DQH   7-9        5-7       Chur
HB9N          7           5          Thun
SN4NMU    8           7          Glogo (Poland)
F5LMH       8           7          Lyon
OE50GMQ 5            2         Spittal/Drau
HB9JB        8            7         Uhwiesen

Here you see the installation of this test close to Basel:

MV-500 comparison
In the foreground the MV-500 and on the car the RoomCap antenna.

State: 15th. July 2005

Antenna report 15th. July.05
Today I performed the first successful test on 20 m with the new antenna
on the roof of a house, on 14.317 MHz from 12.15 to 12.45 MESZ.

Antenna: 1.3m long radiator
Transmitter: TS-50, 100W

The location was on a flat roof in Allschwil (Basel), 11 m above ground
on top of an industrial building.

The antenna was adjusted on 20m, as well as on 40m to a SWR
of 1.0 at 50 Ohms.

20 m Tests:

The following stations from Basel and vicinity were qrv:
HB9PP with GP: CP5 Diamond with 100 W
HB9BPP with Beam 5el DJ2UT with 100 W
HB9EAX with GP: R5 Cushcraft with 100 W (17km distant)

Remote stations:
SM4/HB9ZA nr.Lulea (Sweden): receeived HB9ABX as strongest signal
   Comment: HB9ABX 1.5 S points stonger than HB9PP
IK7LQH Appulien: Strongest signal: HB9ABX, HB9PP not readable
EA6/HB9DNY (Mallorca): Strongest signal: HB9ABX
   Comment: HB9ABX 1 S point stronger than HB9EAX

For next week a longer test is planned at the same location
on 40 m.

Probably next Tuesday afternoon.

Until then ...

State: 19th. July 2005

Antenna test 19th. July 2005 on 40 m.

Band = 7 MHz, flat roof , industrial building, 11 m above ground.
Both stations with 100 Watt.

A longer comparison test on 7 MHz took place between:
GP: Cushcraft R7000 on the roof of a family house of HB9BXS
and the  40 m Roomcap antenna (1.5 m long) on the flat roof.

The test began at 1715h MESZ und finished at 1930h MESZ.
Unfortunately the band was nearly dead and only very few stations
could be heared with weak signals.
One had to search long to find
a station. This one was called and the comparison test performed.

The result was, that in most contacts, both stations arrived with
nearly the same signal strengths, the differences were small.

The test indicated, that in a roof installation the small antenna
equals the performance "of the bigger brothers".

Here follows the worked stations and the
received reports in S points.


DL7WA           8                8             Hof/Bayern
DJ4PZ             8                8             Willhelmshafen
HA/DK7ZU     8-9             8-9         Malaton, Hungary
DC3TS/p         9                9             Waren, North Germany
PE0PSL          8                6              Arnheim, Holland
SO3AD           9                7              West-Poland
G0ECX           9                8              Weymouth UK
G3MCA          9                8              Kent UK
G3FGH/m       8-9             8-9           Grimsby UK
DB2LTU        7 (9)           8 (9)         Heiligenhafen, East sea
M0BBZ          9                8               UK
EA2ID            9+5            9+5           Zaragossa, Spain
EA3BGQ        9                9+10         Tarragona, Katalonia

      State: 22th. July 2005

Here I refer to the test performed on the 13th of July
(extended Microvert comparison).
I received several mails on this subject und would like to
explain why and how the result could be obtained:

Read here: MV-losses

   State: 26th. July 2005

DX result of test  on 20 m from 26th. July, 2005, 20.45 to 22.00 UTC
This is the first time that an antenna comparison of the HB9ABX antenna
 was performed in DX contacts. (DX = large distance, overseas).

HB9ABX = 1.3 m long Roomcap antenna, 100 w PEP, 150 m distant from HB9BXS
HB9BXS = R7000 on the roof of his house, 100 W PEP
Long QSOs with DX stations on 20m gave the following results:

Reports shown are received reports in S points  (averaged in QSB)

Call                 HB9ABX HB9BXS         QTH
K1EKF            3                1                    Evans, Georgia, USA
HB9DTF/mm  3                0-1                 Coast of French Guayana, South America
W1LC             4                2                     Spencer, Massachusetts USA
W1ZY             5                 2-3                 Brooklyn, NY USA
2E1MJH        5                  2                   Clare, UK, not DX

State: 13th. August 2005

Results of 9th. and  12th.August

On August 9th. I made a  Comparison test with a 5-Ele Beam
from HB9BPP. On top of the 7 floors building at the altitude
of 27 m is the DJ2UT-Beam Model 5c installed.
The beam was directed towards the remote stations.
We performed the tests while I was located at a parking place with my
test antenna of 1.3 m length.

Both stationen with 100 W PEP.
The following QSOs  were made between  20.20 - 20.35h MESZ:

Remote Stn.     HB9ABX  HB9BPP
------------------   ------------   ------------
OH5ZZ              59+10        59+20
SM2YZZ           59+10        59+10
LA6TOA           58              58

Surely interesting, isn't it ?

Clay tile roof Test
On August 12th. August we made the first antenna test on
a building with clay tile roofing and wooden understructure.

The test antenna  was mounted vertically in the center of one side
of the roof, the base of the antenna 20 cm above the roofs.
The R7000 was monted on a mast on top of the roof,
abt. 2 m distant from the end of the house.

The test was conduted on 40 m band.

Comparing antenna: R7000 (Cushcraft) with its own radials and
Test Antenna: HB9ABX (1.5 m long).
Both antennas decoupled from each other and connected to the
same transceiver via a coax switch.

Here follows the QSOs with the received reports:

Remote stn.    Testantenna   R7000  QTH              Remark
------------------  -----------------  --------   ------               -----------------
DL1AVP/p          57               57          Isle Rügen    R7000 1 db stronger
DL5DIL              57              57 1/2     Dresden        R7000 1/2 S point stronger
PA/DJ5KP          57              57 1/2     Ost-Kapelle   both equal, sometimes R7000 somewhat stronger
OZ/DK3HG        57-59        57-59       Bornholm       both equal, no difference
DJ4HG               59-59+      58            Rott/Eifel       Testantenna well 1 to 1.5 S points stronger

Then came the unexpected end: The neighbour returned from vacation and was disturbed
by the antennas. To keep freedom, we dismounted all from the roof.
We intended to conduct at least 10 contacts on 40 m and afterwards to perform a test
on 20 m during one hour ...

Interesting note during test on the clay tile roof:
During receiption, the test antenna delivered a clear signal from all stations, while
listening with the R7000 all stations disappeared in the noise, except DJ4HG, who
was the strongest station.
The noise was man made noise, as caused by TVs,
computers, and monitors.
The signal/noise relation was between 10 to 18 dB better, using the test antenna.

This shows, that the antenna operates upwards and suppresses well downwards.

State: 30th. August 2005      DX  DX  DX  DX  DX  DX  DX  DX  DX  DX DX DX

DX-Test on 20 m: To Trinidad (close to Venezuela), South America.
On August 29th we made an extensive  DX test on 20 m.
The duration of the test was over one hour, and beside my test station further
two local stations and one distant station participated as comparing stations.

Test station: Felix HB9ABX, 1.3 m long Roomcap radiator installed on car with 100 W PEP.
      Test site 1 = Parking place "Bachgraben" (Basel-Allschwil)
      Test site 2 = Small hill in Allschwil, street to Neuwiller

Remote station: Beat, HB9DTF/mm in Trinidad, Port-of-Spain, inv.V with 100 W PEP

Comparing station 1 = Sämi, HB9BPP, 5 Ele Beam (DJ5UT) 27m high, 100 W in Allschwil
Comparing station 2 = Ueli,  HB9EAX, Cushcraft R5 mit 100 W PEP 18 km distant
Comparing station 3 = Sigi, OE6KNG, 3 Ele Yagi, 15m high, 100 W in Graz, from 22.35h on

Start of test: 22.00h MESZ on 14.318 Mhz from test site 1.

General remark: The signal from Beat was received by all participants with very large
signal strength variations, rapid QSB in the order of 3 S points, whereby the average
signal strength varied slowly between S3 and S6.

22.00 Start of test: Beat received Felix with R5,  Sämi with R5, and Ueli
    was heared with R1 (not readable, just detectable),
    Sämi arrived a little stronger than Felix, but could not be measured in S points
    due to rapid QSB
22.10: Felix is driving to test site number 2 (duration 8 Min).
22:20h-22.30h Felix noticed a slight signal improvement of Beat signals. Difference minimal.
   Then we performed a number of short changeovers between Sämi and Felix to permit
   Beat to perform a signal comparison:

   Comment from Beat: Sämi and Felix appear to have the same strength, both are readable
   with R5. Difference below 1 S point advantage to Sämi.
  Ueli now with R2 (barely readable).
22:35h : Sigi appears and receives from Beat about 1 S point better report than Sämi.
   Now Ueli can be received with R3 (weak readable), later back to R2 from Beat.
   Felix and Sämi with R5.
22:45 bis 23:00: Several short changeovers between Sigi, Sämi and Felix:
   Comment from Beat: Now all 3 stations arriving with the same signal strength
   in Trinidad. Exact S points cannot be given due to rapid QSB.

Additional info: Between Graz (Austria) and Basel were short skip conditions.
Sigi's signal reached S9+ at some times in Allschwil.

Conclusion: The ABX radiator demonstrated a very good performance in DX communication
for both test sites, in parking place as well as on a slight hill. There was a difference
noticable between test site 1 and test site 2. Signal from test site 1 arrived slightly lower
than Sämi. On test site 2 there was practically no difference between Sämi (5 Ele
Beam 27 m above ground) and Felix!
-    Here follows the email, I received from Trinidad after the QSO:
I nearly can't beleave it, that your antenna is only 1.3 m long, and at my next Cybercafe
visit I will have a look to your homepage.
The strength of your signal was slightly weaker than HB9BPP while at the parking place
in the city, and on your drive.
When arrived in Allschwil on the small hill, there was no difference to detect between
your two signals ...

   State 16th. September 2005:  Last 2 weeks.

         What happend in the last two weeks?  Read here

    For antenna unbeleavers:  (22th. Sept. 2005)
   Michael, DF8WI, visited me and wrote this mail:
   Hello, all interested in antennas <<< (Click to read)

    State 6th. October 2005: 80 m
   The new 80 m construction is finished, here follows the information:
   New 80 m HB9ABX antenna  <<< (Click to read)

    State 14th. October 2005:
Several improvements could be obtained in the last few days:
   20 m and 40 m improvements  <<< (Click to read)

    State 1st. November 2005:
    Power testing of the antenna with high power:
   Test report 1 KW on 20 m and 40 m  <<<  (Click to read)

   State 9th. November 2005:
   Now I was able to build a 3 band version, which I was
   testing and measuring today:
   3 Band Version      <<<   (Click to read)

    State 26th. November 2005:
Good question about the construcion guide of the new antenna:
   Here the answer   <<<   (Click to read)   

   State 14th. December 2005:
   Here the answer   <<<   (Click to read VARYLINK etc.)

   State 31th. December 2005:
Technical functions of the VARYLINK
   Varylink     <<<     (Click to read)

   State 6th. Janaury 2006:
3 Band Antenna: Measuered values and picture
   20-17-15m antenna   <<<   (Click to read)

    State 16th. Febr. 2006:
    During January/February tests were performed in Chile on 20m and 40m
   Chile Tests    <<<  (Click to read)

    State 1st May 2006:
   A new antenna version: 2 band RoomCap for 20m and 30m
   20-30m antenna   <<<   (Click to read)

    State 28th May 2006:
    Experience on 80m (mobile installation)
   Report 80m   <<<   (Click to read)

    State 1st June 2006:
   New antenna version for 10/11/12 m
   10m RoomCap   <<<   (Click to read)

    Explanation 29th June 2006:
   Why is the small RoomCap so efficient ?
    Efficiency of the RoomCap Antenna  <<<   (Click to read)

     State 15th July 2006:
    Field strength measurements RoomCap
    Measuring results 20m   <<<   (Click to read)

     State 4th August 2006
New version: 160 m RoomCap (power capability 1 KW SSB)
    160 m test reports
    <<<   (Click to read)

    State 6th September 2006
     160 m antenna at 2% and 1.25% of wavelength
    160 m antenna shorter and shorter   <<<   (Click to read)

     State 24th October 2006 / UPDATE 28th Oct 2006
Comparison with G5RV : VE3UNF + ON6EJ
Here are the reports     <<<    (Click to read)

     State 29th October 2006 / UPDATE 12th Nov 2006
Life demonstrations of the RoomCap antenna
     Dates and reports  <<<   (Click to read)

     State 7th November 2006 / UPDATE 14.April 2007
80m SWR bandwidth as Excel sheet + picture of anteanna
     Here is the bandwidth data   <<<   (Click to read)

      State 30th November 2006
Comparison with Magnetic Loop antenna
     Here is this report   <<<   (Click to read)

     State 1st December 2006
    Comparison with EH antenna
     Here is this report   <<<   (Click to read)

       State 19th March 2007
RoomCap antenna simulation with NEC
      Read report here   <<<    (Click to read)

        State 14th May 2007
        Comparison with Titanex GP 40-10
Here is this report   <<<   (Click to read) 

        State 22nd May 2007
        Builder report from Germany, DL5GBP, 40m band
Here is this report   <<<   (Click to read)   
        State 9th June 2007
        Report of antenna measuring with MiniVNA antenna analyzer
Here is this report   <<<   (Click to read)    

         State 15th July 2007  
         Reply to critics of RoomCap antenna
Here is this report   <<<   (Click to read)         

        State 17th September 2007  
        Comparison with horizontal loop antenna
Here is this report   <<<   (Click to read)          

        State 16th. February 2008 
        On 40m : DX experience
Here is this report   <<<   (Click to read)  

      State 11th April 2008
Antennas and Physics, technical article
      Here is this report   <<<   (Click to read)   
      State 18th May 2008
RF/DC separator eliminates control line
      Here is this report   <<<   (Click to read)    

      State 1st June 2008
BIG SUCCESS: Antenna test by Military
      Here is this report   <<<   (Click to read)  

       State 4th December 2008 (update Dec 15, 2008)
Super DX results on 80m
      Here is this report   <<<   (Click to read)    

        State 4th January 2009 (update Jan 13, with 80m result)
Results from Puerto Rico: Comparison with fullsize Vertical on 30/40m
      Here is this report   <<<   (Click to read)     

        State 11th February 2009
160m DX Antenna in Puerto Rico
      Here is this report   <<<   (Click to read)           

        State 14th June 2009
User comment about the 160m Antenna
      Here is this report   <<<   (Click to read)     

       State 10th April 2010
80m Antenna at DL2SBF  (very, very satisfied)
      Here is this report   <<<   (Click to read)    

        State 14th April 2010
80m-DXCC with Roomcap  (JA8CNF)
      Here is this report   <<<   (Click to read) 
        State 3rd July 2010
Roomcap user comment  (EA8AYT)
      Here is this report   <<<   (Click to read)

        State 27nd November 2010
Roomcap in the Internet 
      Here is this report   <<<   (Click to read)   
        State 5th January 2011
Presentation of VARYLINK and RFA 
      Here is this report   <<<   (Click to read)

        State 29th January 2011 / 30.3.2011 
Frustration and Success from DL9PB  
      Here is this report   <<<   (Click to read)
       State 7th April 2011  
RoomCap rocks! (AC8CE)  
      Here is this report   <<<   (Click to read)

       State 10th November 2011  
Antenna - analysed  
      Here is this report   <<<   (Click to read)

        State 22nd November 2011 / Upd 20th Dec 11  
RoomCap as super CB antenna (11m)  
      Here is this report   <<<   (Click to read)

       State 5th December 2012   
Impressive Demonstration between houses, 2nd generation  
      Here is this report   <<<   (Click to read)      
       State 27th April 2013   
2nd Generation RoomCap: more  
      Here is this report   <<<   (Click to read)     

       State 28th July 2013 / 9th Aug 2013 
2nd Generation RoomCap: and even more: now all bands 10-80 m
      Here is this report   <<<   (Click to read)        

       State 12/16th October 2013
2nd Generation RoomCap: In action in CW on 15-17-20m
      Here is this report   <<<   (Click to read

       State 1st February 2014
Nice Roomcap construction by HB9CPD
      Here is this report   <<<   (Click to read)    

       State 5th February 2014
Roomcap QRV on 4 bands
      Here is this report   <<<   (Click to read)   

        State 21th June 2014     
        THEORY to Roomcap !!!     
        Here is this report    <<<   (Click to read)               

        State 23th June 2014     
        Antenna comparison with RBN!      
        Here is this report    <<<   (Click to read)                                      

        State 26th November 2014     
        QRV in the car - 20m - worldwide!  
        Here is this report    <<<   (Click to read)

        State 13th February 2015     
        40m QRV in the car -- worldwide!  
        Here is this report    <<<   (Click to read)      
      State 30th September 2015     
        40m public demonstration - car - with video!  
        Here is this report    <<<   (Click to read)    

        State 23th Februar 2017     
        60m-Version Roomcap  
        Here is this report    <<<   (Click to read)  
        State 6th April 2021
     I can't send, because I had a stroke, sorry.

The Tests are going on. Will keep you informed here. Please check in frequently to see ...
Felix Meyer HB9ABX

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