22 de setembro de 2013

HF Antenna Project


After completion of assembling, profiting to  improve some mechanical details, specially in what concerns protection against elements and replacing boom-to-mast clamps by others specially made in SS and heavy duty (those which were coming with the antenna are equal to those of the elements and simply very weak, at sight),

The antenna was ready to go up. Ginpole (pipe 60 mm ext. Diameter,  6 m long which 2,5 m  outside of tower) with steel hoist (with two sheaves) was installed and fixed to the tower by special clamps...
Due to the fact that my , being triangular, with 70 cm side , 2 elements (S12, S20, S17) plus S10, wewre slided in the boom but out of final position to allow the boom 'slide' in the tower when raising. Boom to mast clamp and nearby areas were provisionally protected with one rubber mat to avoid deterioration.

Usual team was also ready: CT1EGW (Arlindo), CT1EEQ (Luis), CT1DIZ (Alex), my brother and me.

The weather was very hot (expected 34ºC in Lisbon) but wind speed nil, so...

Unexpectedly the unbalance was almost nil , even , instead, a little unbalance but of the front of the antenna ! Good news!
Also the force necessary to hoist it , was low and so low that one person could do it!, so everything was going smoothly , rising...

Suddenly one of the clamps attached to the ginpole slided and the whole set come down a couple of meters, fortunaley slowly but everybody was freezed under 34 ºC !!
Things were corrected and one additional winch was mounted , and the antenna rised again without problems perfectly stabilized, which is amazing...

and up to the top. To attach it to the mast, due to a slightly deviation between the ginpole and the mast, has given some work but the crew up there have lots of experience in similar situations, and finnally OB 13-6 was at the top without damages !

As soon as the antenna got there I've assembled my mobile station in the attic and also with one MFJ antenna analyzer SWR was checked all across all 6 bands and all FB!

Vy 73 de Luis, CT4NH

HF Antenna Project


Following last messages , and with AB-105 tower ready to receive new HF antenna , I've dedicated my free time to finnish the assembling of OPTIBEAM OB 13-6 antenna. Having read a lot about this little monster , specially about its infamous unbalance , which means that manufacturer could not locate boom-to-mast-plate at its gravity center (as a matter of fact antenna has a very strange look if center plate is located strictly according assembling manual , between S12 and S15) and rear of the antenna will then be sloping backwards...which eventually will give also lots of trouble for those who do not have an HAZER, telescopic tower or crane to hoist it, which is my case! Remember that this antenna weights somehow 75 kg and has lots of 'wing'... 
Knowing this, the manufacturer give an option, which is to locate the Boom-to-mast-plate a little bit to the back between S10 and S17, but considering the critics I've read (and specially PY6GZP description...) I was 'terrified' about to have the antenna completely sloping backwards when hoisting it...

As my tower is located in one corner of my attic (6,5 m x 5,5 m), I could not just simply start the final assembling without assuring that I would have acess to parts of it that could be inacessible, so I got back to my drawing table and made some planning with scale models...not easy for those who dont have enough space! The choosed position should be the one from where the antenna will be hoisted. No doubt about this!
So with the precious help of my good friend Arlindo, CT1EGW and several scaffolding 'borrowed' from a nearby contractor...

I've decided to put the antenna as close as possible to the tower with center of it in the vertical direction of the ginpole...

Due to the assembling position,  front of antenna - then completely assembled with all its elements - was sloping a lot so I had to use 3 jerry cans (about 40 kg) full of water hanging them from the rear part of the boom and then assemble longer elements (reflectors).

HF Antenna Project


Ham Radio... Replacing my Radio Tower !

The option I've took to replace my tribander for one multibander (6-band) beam brought other problems...mainly mechanical ones.
In fact the Optibeam OB13-6 weights 75 kg!
My previous KLM tribander weights 35 kg...

The tower where I had my previous antennas was in steel, home made inspired on Rohn 35. It was almost 20 years old, but still in very good condition.
After lowering the KLM I begun searching around for other Optibeam OB 13-6 owners and , specially, what type of tower they were using with it, what means they have used to hoist it to the top of the tower, etc., considering my local conditions: tower is erected in one city lot, no space for crane whatsoever, and limited space to assemble the antenna on ground. So one big challenge!
I've got in touch with OE6TGD (Gerhard) who, kindly, sent me several photos of his assembly odissey , and I should bow as it was a one-man-job. Incredible ! If this guy has done it, I will do it also! He has assembled  whole antenna in the top of the roof and , alone !, put it in top of the mast.

The man :

Final result !

After this, I've kept searching, and in another completely different scenery I found PY6ZGP (Guido, also DM1GP) at Canavieiras, close to Bahia in Brazil, who has one OB 13-6 up in one aluminum tower with hazer system to hoist the antenna...quite comfortable. Again, very kindly he sent all details about his assembling , also some important tips concerning the infamous unbalance of this antenna...

Below photo shows Guido passing to one local, the 'extra weight' he has inserted inside the boom to compensate the unbalance of this antenna (depending on the place where you assemble the boom-to-mast plate). Consists in one pipe full of metallic litter (about 12 kg he estimates) that goes into the end of the square boom.

Beautiful scenery !

After these 'experiences' and some meditation, I've decided to replace my tower as obviously it was out of question that it will support the high torque and weight of this antenna. So looking for one strong one I had many years ago, the AB-105 Military Tower which belonged to late CT4AT, Don Riebhoff (ex-K7ZZ , 1S1A , XU1DX ) and also my very good friend, to whom I've bought it back in 1987. I've used this tower with KLM monobanders and so, but  about 20 years ago I've decided to maintain only one tribander , and offered AB105 to close friends (I had about 36 m of it) .I've contacted CT1DIZ (Jose Alexandre) that still had 12 m of it in the garden of his mother's house, so I asked him if it will be possible to return it to me...no problem. So off we go.
Knowing these type of towers very well, and after many months of restoring process, it was completely  painted , manufactured many parts (support plates for rotator, new bearings etc) having all these parts hot galvanized, replaced all bolts and nuts,  added proper steps ( and in last section steps in 2 sides) and  finally assembled (and disassembled)  it in my yard in order everything will fit when up...

Home made bearings

Every section numbered and pre-assembled

Proper steps

Sturdy guy wire anchoring point (the tower will be guided in 6/12 m level...just in case...I live about 1 mile from the Atlantic Ocean...)

In the meanwhile I was assembling the antenna in the terrace just close to tower foundation...

So the day arrived and our group of friends (CT1EGW,CT1EEQ,CT1BGE) helped to put it on the air and install all guy wires. Ready to receive the antenna...


CT1BGE (Luis), the 'winchman'...

CT1EGW (left) and CT1EEQ in the tower


HF Antenna Project


Ham Radio...Changing my antenna system...

A couple of years ago I've decided to replace my faithful antenna (KLM KT 34XA) that was on the air for about 20 years, already showing sign of times and hard use. The important fact that it doesn't cover WARC bands weighted in my decision, as since these bands were allocated to hams I had to work them using very simple wire antenna systems, loosing a lot of DX so far! Also helping, those repeated and never ending problems with the rotator Yaesu 2800 SDX, showing (since the first day!) more and more an erratic behavior, stopping , starting at its own will...rotators are ham's nightmare...
Its difficult and very frustrating for one that has been on the air , without interruption, since 1977, to stay away of Radio without seeing the 'end of the tunnel'...and , worst, hearing other DXers telling this and that about announced DXpeditions, DXnews causing us all time, and so...not easy.
Decision taken, and KLM down, perhaps too early.

As usual, my good friends CT1EEQ (Luis Rodrigues), CT1EGW (Arlindo Ferreira), CT1BGE (Luis Costa) and old 'DX fox', CT1BWW (Marques), helped me since the first day. In the above photo , CT1EEQ and EGW waving good-bye KLM...

At this time I had already another antenna in the garage: the Optibeam OB 13-6...big and expensive, we will see  if its performance is also as spec sheets show...

So, profiting a long and rainy winter (so far ended, crossing my fingers) I start assembling 'the' OB, and immediately I've verified the meaning 'made in Germany', strong, detailed and very well conceived. I should clarify that  all my previous antennas (mostly all kind of Yagi beams) were 'made in USA'. The important parameter - weight - confirms that you cannot have everything in one package...far from that, but time of monobanders are gone.

So several photos of  "OB's " assembling.

In the above photo we can see one can of a miraculous liquid electrical tape (known brand name) , but as every dark cloud has a silver lining...due to tower decisions (later in next episodes :-) ) my antenna has been partially assembled in the terrace, open air, for more than one year (one hot summer and one very rainy winter) , I can now see that the liquid electrical tape is cracked and peeling...and not, yet, getting strong winds..so...

The photo above shows the boom-to-mast-plate, but this one 'home-made', in stainless steel, as the original one (aluminium) seems, in my opinion, not strong enough. Still to decide if I will use mine or Optibeam's plate (much lighter)...but it impresses how one 70 kg antenna+all stress inducted by external factors (wind, etc)  is supported by those (not those showed on pic, because they are quite sturdy) little 4 clamps coming in the package. Still to decide.I know that assembling SS parts with aluminium ones can lead to some kind of electrolytic corrosion, but this situation is common specially when bolts, washers and nuts are SS.

The above photo shows the excellent quality of manufacturing (connection of boom sections). The black 'tape' seen (not provided by Optibeam) is not an ordinary tape, but that one called 'DENSO' tape, normally used to isolate underground piping connections. Literally indestructible, very difficult to remove.

Every connection was carefully sealed with industrial compound (brown colour) and every telescopic connection treated with anti-seize copper compound (best, in my opinion is industrial vaseline! never dries!) Also, in all connections, I've applied , first one layer of self vulcanizing tape then covered by (good) 3M electrical tape.

23 de abril de 2013

I'm also nuts about Daschund Teckels , so here it is one cool poster! And amazingly it's TRUE!

15 de dezembro de 2012

My other Mini Cooper, one Austin Cooper MK2 1968 lives almost all year round in a barn in countryside together with other machinery...I've bought it many years ago already 'restored' as one MK2 S replica. Pure naivety...
Nowadays, after having seen several MK2 S's, and read a lot about them (what I've should done in first hand !) ,  and restored one MK1 S, I should agree that apart its good looking and good reliability it's faraway from the original...

I've thought to 'return it ' to its original DNA (Cooper MK2) but the costs were high, and as I already have S bits in it, I've decided to improve and correct some of its unconformities , at least most of them...
So after some recent issues with speedometer and odometer (both stucked) , I took the binnacle and  all instruments off from the dashboard , made some serious reading about similar 'diseases', followed by one complex surgical intervention and transplantation by Doctor M. gold hands (odometer worm and gear were replaced from another donor), both units were ready for more rpm! As above mentioned all articles I've read about this type of  'diseases' and expert's opinions were very skeptical, discouraging interventions by amateurs...so against all odds the repair was sucessful!


So I've corrected some of its unconformities, but still faraway from the end, and , as usual, it will be a never ending story ... but all of those historical bits (genuine Restall recliner seat, genuine John Aley rollover bar (back) , etc) will be kept obviously.
Fot the time being I've beggined by the engine bay compartment...and being one MCR (Mini Cooper Register) member, I've exchanged some e-mails with Cooper S MKII Register, Nick Hunter, who helped me with some photos of its unrestored (!) MK2 S which engine bay  was as showed, an authentic time warp machine !

Mine...as it is now and 'under costruction'...

Keep tuned...

30 de novembro de 2012

Anos 60...meninos da "linha" !

Os Cooper foram, nos anos 60 o carro 'da malta', e esta foto ilustra perfeitamente essa juventude irreverente (segundo os padrões da época), especialmente o dono da 'máquina', de óculos Ray-Ban e luvas de 'dedos cortados' rodeado dum grupo de 'meninos da linha' ;-). Curiosamente trata-se doutro radioamador, o CT4HN, o 'Quim' . As 'transformações' da época' (o tuning...) limitavam-se, na grande maioria dos casos a "isto"...

E com outro artista...

Curiosamente não tirou os tampões - transformação mais comum na época , e que , seguramente, lhe daria mais uns 'cavalitos'...
Obrigado Quim!


28 de novembro de 2012

To my friend CT1BOH, José Carlos Nunes

Apart from my (recent) hobby of restoring Mini Cooper (exclusively sixties) I am Radio Amateur (callsign CT4NH) since 1977... and in this fantastic hobby I've dedicated all my time, from the very first day I should say!, to  the elusive intercontinental contacts (known as 'DX') and especially to Contests. This forced that my ham station was equipped with very large antennas, to participate - with minimal success at international level - in Radio Contests, situation only possible due to the space I had, and the absence of severe restrictions for radio amateurs living (the vast majority) in cities or urban lots. Today it is virtually impossible to erect one suitable and competitive antenna in one of those apartment buildings, without being persecuted and prosecuted !

Some 30 years ago, there were already some constraints, not so severe as nowadays, and by this fact, one very young Jose Carlos Nunes (then a teenager), with callsign CT1BOH, often used my station in various Contests, always competing in telegraphy ('CW') and demonstrating exceptional skills not only in listening/decoding (most important!) as in high speed transmission. In fact his station was located at his parent's apartment - in Lisbon - and he had no possibilities to erect competitive antennas for all amateur bands.

His expertise, his various titles of World Champion in CW (Telegraphy), led other hams around the world, to invite him to participate from their stations on several Contests, which the most prestigious one is CQ World Wide Contest sponsored by the american magazine CQ Amateur Radio, and taking place every year in the last week-end (48 hours) of November. The above photo shows Jose Carlos CT1BOH operating from Madeira Island ham radio station - belonging to Madeira DX Team - and going for another World title on the top category : Single Operator All Band High Power! Just to give an idea about the technical sophistication of these Contest stations below the description of showed lay-out (operating with 2 radios simultaneously), as proof that the Ham radio operator should not only have the skills to transmit and receive/decode at speeds reaching 50 to 55 wpm (words per minute) but also to have a complete control of all the paraphernalia of equipments and antennas ! Well done Jose Carlos ! 

1- Linear / radio1 (manual tuning)
2- Stack match to select beverage to EU, Beverage to USA or both at the same time.
3- Radio 1 (mostly on RUN)
4 - Band Pass Filter to radio 1
5 - Band decoder for automatic antenna switching and logger for radio1
6 - Band display ( from 2khz to 200khz). Mostly Radio 2 (Search&Pounce > S&P)
7 - Radio 2 (mostly S&P for multipliers)
8 - Band pass Filter for radio2
9 - Band decoder for automatic antenna switching and logger for radio2
10 - Logger Win-test SO2R (Single Operator 2 radio) advanced mode
11- 13 coax cables to antennas (2*10, 2*15, 2*20, 2*40, 2*80, 1*160, 2*beverages)
12 - Stack match for antennas 80 m band - EU, USA ou EU+USA
13 - Stack match for antennas 40 m band - EU, USA ou EU+USA
14 - Stack match for antennas 20 m band - EU, USA ou EU+USA
15 - Stack match for antennas 15 m band - EU, USA ou EU+USA
16 - Stack match for antennas 10 m band - EU, USA ou EU+USA
17 - Extreme Isolation headphone inhibiting external noise (linears)
18 - Not visible - Linear to radio2 (automatic)


21 de maio de 2011

Rally do Benfica 1966 - Regresso ao passado!

O encontro que tive esta manhã já vinha a ser agendado desde há quase 4 anos! A ideia inicial era juntar a equipa que participou com o GE-90-01 o Rally do Benfica 1966, isto é o Carlos Edmond Santos - Manuel Coelho da Silva e proporcionar-lhes um 'regresso ao passado'!
Infelizmente o Carlos Edmond Santos já nos deixou , mas tenho mantido contacto assíduo com o seu 'pendura' (termo da época, actualmente 'navegador'...) não só nesse rally como em muitos outros em que brilhantemente participaram,
Decidi finalmente ir ao encontro do Sr. Coelho da Silva.
Um 'jovem' de 78 anos que, ao ver o Cooper, disse de imediato: 'Era verde!'...de facto este Cooper S MK1, como todos os CKDs da época, era 'monotone' verde. Em Março de 1965 o Carlos Santos alterou o livrete para 'verde e outra' e pintou o tejadilho de branco (Old English White).
A alegria do Coelho da Silva foi enorme e pudemos dar umas voltas com ele a 'cantar' umas notas á boa maneira da época , usando os mesmos termos e tudo. E não perdeu 'a mão'!
Ficam aqui algumas fotos que servem de pequeno agradecimento ao Sr. Manuel Coelho da Silva pela sua extraordinária memória que me permitiu reconstituir o historial do carro, nos seus primórdios, a era mais importante.
Na foto acima MCS recorda os momentos em que nas etapas nocturnas substituia o Carlos Santos 'à roda'...
Na foto acima 'homem e máquina'...
Na foto acima , á semelhança daquela que foi tirada pelo famoso fotógrafo Ávila á dupla Carlos Edmond Santos / Manuel Coelho da Silva à porta do Estádio da Luz em 1966, aqui, uma foto tirada junto ao Casino Estoril num local tantas vezes palco de complementares do Rally TAP, Volta a Portugal, etc!

Como ilustre Seccionista do Sector Automóvel  do Sport União Sintrense - que a muitos de nós proporcionou, nos anos 60, belas provas na Base Aérea da Granja do Marquês - o Sr. Manuel Coelho da Silva teve a gentileza de me oferecer uma medalha comemorativa das 3 Horas da Granja do Marquês de 1969 !

Obrigado Sr. Coelho da Silva !