Transmatch automat
Gheorghe Andrei Radulescu YO4AUP
Sigur ca aceste imagini va duc cu gindul la ceva frumos, elegant, care nu se strica niciodata. Si desigur are motor. Precis nu ne gindim la acelasi lucru. Eu ma gindesc la ceva frumos, elegant, care nu se strica niciodata, dar cu doua sau trei motoare! Ati ghicit ca este vorba despre Rolls-ul transmatch-urilor automate? Stiti care este acesta? Nici eu nu am stiut pina acum, dar am aflat. Am colindat licitatiile pentru aparatele la mina a doua de pe piata americana si iata ce am gasit in perioada 1-11 octombrie 2005.
Plimbarea are loc la adresa http://www.ebay.com/ si cuprinde vizitarea paginilor pentru ofertele urmatoare (item number ordonate in ordinea alfabetica a producatorului):
5815872057 Heathkit SA-2500 11oct2005 510.00$ 16 oferte
5815585319 ICOM AT-180 06oct2005 292.00$ 11 oferte
5813986259 ICOM IC-AT 500 05oct2005 466.89$ 13 oferte
5812826684 J.W.MILLER AT2500 02oct2005 645.00$ 10 oferte
5814337609 J.W.MILLER AT2500 04oct2005 611.00$ 32 oferte
5815927278 KENWOOD AT-250 09oct2005 133.00$ 13 oferte
5814985376 L.D.G. AT-11mp 06oct2005 81.00$ 8 oferte
5815248553 L.D.G. AT-1000 09oct2005 356.00$ 9 oferte
5814305223 YAESU FC-757AT 06oct2005 228.25$ 27 oferte
Separati aceste aparate in doua categorii: sub 300W si peste 300W. In continuare discutia se poarta numai pentru transmatch-urile peste 300W adica, tot in ordine alfabetica, Heatkit SA-2500, ICOM IC-AT 500, J.W.Miller AT-2500 si L.D.G.-1000. Acesta din urma face parte din generatia noua echipata cu microprocesor, dar fiind disponibil pe e-buy la inceputul lui octombrie, l-am prezentat si pe el.
Fara concurenta se detaseaza in prima linie transmatchul fabricat de J.W.Miller, AT2500. Citeva pareri despre acest transmatch se gasesc publicate la urmatoarea adresa: http://www.eham.net/reviews/detail/968
De la aceasta adresa am extras pentru cei care nu au internet o frumoasa descriere facuta de K6RUS in anul 2000. Nu am tradus intentionat acest text pentru a nu-i strica culoarea locala:
"I wanted an automatic tuner for my newly acquired Ameritron ALS600 solid state linear and my research came up with few alternatives, all expensive and most obsolete. The J.W. Miller was made by a division of Bell Industries and I was able to buy one of the last made, a 1996 model. I hesitated to buy this tuner because it is 17" wide but I decided that my linear and Yaesu speaker cabinet would fit nicely on top. Now my Yaesu FT847 is dwarfed along side this set up. The AT2500 is a marvelous piece of engineering, it tunes fast and is very quiet and you only need to select the band letter (D or E for me, 10-15-20), set FT847 mode to FM and if you are polite, reduce your Xcvr power, then press "Start", it rapidly tunes to the SWR setting you have selected. My linear wants less than 2.5:1, so I leave the tuner set to 2:1. It will also control your linear, if it is not a "no tune" type. It comes with a coupler-bridge that goes in the RF line, so make sure the tuner comes with one of these little boxes, or you will need to build one from the drawings in the manual. You can "tweak" the tuning if you wish, e.g. move one of the two dials a little and you will see the SWR meter move right on down to 1:1 although the linear did not seem to care if it was 1:5 or 1:1. I had fun, turning a dial and then pressing the "start" button, watching closely the knob will rapidly turn back. It remembers one setting for each band. It does not automatically tune though, unless asked although there is a "tracking" feature that can be utilized. I noticed that it required less re-tuning than the MFJ986 I was using before, I wonder why? Design quality, perhaps? The manual says for SSB, it is not desirable because it requires a constant carrier. I tested it on 80 and 40 meters, same great results. I also tried it with a Butternut H9V as well as the Mini-Quad, makes the linear happy with either. If you like "bells and whistles", it has 'em! Panel ights to say what it is doing, audible alarm (on/off) if it can't tune the selected SWR, e.g. you tell it you are on one band but tune your xcvr to another. In this case, it has a standard sequence it goes through in attempting to match the impedance. An exciting to watch exercise as one dial turns and then the other. Lots of features, multiple antenna connections/switch settings and push buttons for various features. The tuner's appearance and color goes well with the modern Yaesu line, except for size. Inside, the construction is clean and high quality, lots of room and not much to go wrong. It is reported that all of the components are standard, lots of DIP chips on the PC board and only two small motors. The manual is for both operators and techies, you could probably build one of these from the information in the manual. Too bad they are not still making these and it is very unfortunate that they did not make a much smaller model that would handle a third of the power. If I sell my linear, the tuner will stay as I like it better than the modern Yaesu FC20. If I buy more power, I will still need this tuner unless of course I sell my car and get the Yaesu Quadra system / care ase transmatch automat incorporat / . So if you want power and be feee from twisting knobs, get a no tune linear and one of these but expect to pay about $750-$850, if you find one for sale. They sold for over a thousand bucks new like the no longer produced Ten-Tec model 253. I guess the market just wasn't there for expensive automatic tuners."
Din pacate,in urma cu putini ani, divizia JWMiller a trebuit sa renunte la fabricatia de transmatch-uri din cauza concurentei facute de MFJ cu produse de o fiabilitate mult mai mica dar care totusi au invadat piata deturnind oparte din cumparatorii potentiali de produse de calitate. Amanunte la sfirsitul raportului de la adresa urmatoare:
http://www.bellind.com/r/news_articles/shareholder_remarks_2003.cfm
***
Remarks from the Bell Industries Annual Shareholders' Meeting - May 28, 2003
J. W. Miller
Bell's smallest business, J.W. Miller, had a down year in 2002, a direct result of conditions in the electronics marketplace. We sell inductors, coils and chokes, and other small electronic parts to distributors and contract manufacturers. A trend we are keeping an eye on, and where we are positioning ourselves, relates to the sourcing of these products from offshore locations, primarily Asia. J.W. Miller has taken steps to establish relationships and capabilities in these markets to ensure that our brand continues to be well positioned in the broad market.
J.W. Miller had a record year in 2000 when sales exceeded $13 million, reflecting strength in the telecommunications and electronics markets at that time. The drop in both of these markets in 2001 and 2002 directly impacted results. Early results this year, including backlog, indicate that 2003 will be better. We generated about $300,000 in profits on $1.6 million in sales in the first quarter of 2003, a substantial increase in income over the 2002 first quarter.
Thank you for joining us.
***
Si cum am inceput acest articol cu un nume care trebuie mai ales vazut, in continuare pozele acestui Rolls Roice al transmatch-urilor automate:
Fig. 3 JWMiller AT-2500 Panou frontal
Fig. 4 JWMiller AT-2500 Panoul din spate
Specificatia tehnica:
Domeniul de lucru: 3.0 la 30 MHz .
Puterea la intrare: Peste 2500 W PEP.
Impedanta la iesire: 10 la 300 ohmi rezistiv (VSWR 1:1pina la 6:1)
Conectoare la iesire: 3 Coaxiale , 1 Antena filara, 1 Coaxial Bypass.
Dimensiuni: 432x134x356 mm.
Furnitura include si o punte de masura de radiofrecventa pentru formarea semnalului de eroare de fabricatie J. W. Miller .
Acord automat < 15 sec cu excitatie mai mica de 1W .
Borne de iesire pentru includerea sau scoaterea liniarului din linia de emisie.
Alarma optica si sonora pentru depasirea VSWR-ului prestabilit.
Blocarea automata a liniarului la depasirea valorii prestabilite a VSWR-ului.
Setarea manuala a valorilor de prag pentru VSWR-ul maxim la iesirea liniarului si la declansarea alarmei.
Doua microampermetre cu iluminare din spate , pentru indicarea VSWR-ului si a puterii la iesire.
Fig. 5 Partea de Transmatch
Fig. 6 Automatica
Toate amanuntele se gasesc in manualul de operare care este completat si cu multe informatii despre service si chiar cu amanunte despre partea de proiectare, astfel ca celor cu mai multa experienta le este cu putinta chiar sa-l reproduca.
Fig. 7 Coperta Manualului realizat de W7FG
Acesta a fost pe scurt o povestioara despre Rolls-ul transmatch-urilor automate din era de dinaintea microprocesorului. V-a placut? S-a vrut si ca o invitatie la o navigare instructiva prin e-buy.
Alte poze cu J.W.MILLER AT-2500
Fig. 8 Panoul frontal-stinga
Fig. 9 Panoul frontal-dreapta
Fig. 10 Buton pt setarea pragului VSWR al liniarului
Fig. 11 Detectorul de semnal de eroare
Fig. 12 Schema conexiunilor pe panoul din spate
Fig. 13 In timpul acordului
Fig. 14 Transmatch acordat
Fig. 15 Rolls-ul transmatch sau Transmatch-ul Rolls
Celelalte concurente la titlul de Miss
Fig. 16 Heathkit SA-2500
Fig. 17 ICOM AT500 panou frontal
Fig. 18 Icom AT 500 interior
Fig. 19 Kenwood AT 250
Fig. 20 LDG AT1000 panoul frontal
Fig. 21 LDG AT1000 interior
Fig. 22 Yaesu FC-757AT
- Gheorghe Andrei Radulescu YO4AUP
-
Articol aparut la
19-10-2005
83578
Inapoi la inceputul articolului
|
