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About G4TPH.com

PW has done a new review of my 2 models of antennas. click here to see the review

 A bit of History about Me

My Name is Tom Brockman and G4TPH is my British call sign. I was first licensed in the USA as K8VST in 1961. Due to Military service I ended up living in England and married a British citizen. In 1982 I did the British exams and became G4TPH.

I have always experimented with antennas and tell the story about loading up an aluminium garden chair on 6 meters in the 1960’s using 90 watts, a Heathkit transmitter, and AM mode. (A 5 element Hygain beam was the usual antenna used).

The reports were “ you’re not as strong as usual”. My response was: “I’ll move my chair” You can imagine how the rest of the QSO went.
  
I have been an active member of the Newbury and District Amateur Radio Society (NADARS) for many years. I am also a memeber of the International QRP club.
    
I attended The Dayton Hamfest in 2008 having carried 40 antennas in my luggage. I sold all. Due to the recession I haven't attended Dayton hamfest again. 
 
I now have reduced the range to only 2 models. Once you get the best possible it is hard to make any improvments. The 2 models are the ML40 MK11 remote tune and the ML40MK11 Manual tune.  Both will tune 40m throught 15m and using only 7 rails they will tune 12m and 10m.
 
Development of the G4TPH Magloops
My wife and I bought a holiday apartment in Spain in 2007. Wishing to do some operating (while the wife was in the pool as you do) I bought an FT817 and a Miracle Whip. Well I stuggled to make any contacts with this and decided there must be a better portable antenna.
 
I then built a wire magnetic loop antenna designed by G4FON. This worked very well. I decided that my magnetic loop antenna needed to be portable and self supporting so came up with the idea of using aluminium rails and a single Air-Spaced capacitor instead of beehive capacitors.  After several design changes I finally had a portble magloop antenna that covered 40 metres through 20 metres and would give an SWR of 1.5 or better on each of the bands.
 
I showed this antenna at the NADARS Radio Rally the summer of 2007. There was so much interest in how well it worked I started making up a few (10 off initially).  This was the birth of the ML-40 Magloop. I have now developed several new models all being improvements on the original designs.

The orginal G4TPH portable Magloop antenna (The rails were 10mm X 2mm.) I now use 16mm X3.3mm rails

Magloop Full ML-40

 
I then decided with the possiblity of some sun spots possibly coming soon I would like to be able to operate on 15 and 10 metres.
This lead to the development of the ML-20 that tunes 20 metres through 10 metres. ( discontinued )
 
During the Spring of 2010 with sporatic E openings on 6 metres I then devloped the ML-6-2.  Once this antenna was developed for 6 metres testing showed it tuned quite well on 2 metres also, thus the name ML-6-2. This antenna requires no tuning as you move frequency across the 6 metre band and provides an SWR of 1.3:1 across the band (2.1:1 across 2 metres) Unlike the ML_40 and ML-20, the ML_6-2 will handle 50 watts power. (Also now Discontinued)
 

The orginal ML-20 and ML-40 antennas have now been replaced with the ML-40 MKII with improved performace. 

 
See the product page for more details 

Please Note:  it is not possible to upgrade the orginal ML-40 and ML-20 to MKII models.
The new MKII models have been totally re-designed and no components of the original antennas are compatible with the new MKII antennas.
 
A bit of current operating (using the ML20-MKII hung from the ceiling rafters of my workshop) 
 
These contacts were all made in the middle of an international contest.
 

Date

Time

Freq

Mode

Power

Contact

Sent

Received

26-3-11

12:53

28.468

SSB

5

D4C

59001

59049

26-3-11

12:04

21.245

SSB

5

RM3F

59002

591337

26-3-11

15:18

14.243

SSB

35

S50K

59003

591015

26-3-11

15:20

14.247

SSB

35

9A7A

59004

59714

26-3-11

15:28

14.267

SSB

35

HG2011N

59005

59763

26-3-11

16:52

14.287

SSB

35

9A1P

59006

59860

26-3-11

16:58

14.320

SSB

35

S520SLD

59007

591149

26-3-11

17.03

14.315

SSB

35

OL9Z

59008

591007

27-3-11

09:10

21.252

SSB

35

RL3A

59009

594081

 

Equipment,

5 Watt, FT817,

35 Watt FT857,

Antennas: ML-20 MKII  

       (the new ML40MK11 remote and manual tune antennas cover these bands now with improved performance)

 

Position: Mounted horizontally in workshop ceiling.

Conditions: Massive International Contest in progress.

 

 

 

 
 
 

 


 

 
Copyright G4TPH.com
57 Ramsbury Drive, Hungerford, Berkshire
RG17 0SG
England

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