Savez-vous de quoi il s'agit ? Non ? Alors cliquez sur l'image- TNX Uli DK4SX

Cette amicale, comme son nom l'indique, a pour objet de regrouper les (heureux) utilisateurs de matériel d'émission-réception Drake, de fournir une aide par le biais du site, de créer un lien, de nous connaître et
d'échanger autour de notre expérience.  
Il n'y a pas de cotisation ou autre formalisme, y contribue celui qui le souhaite, aucun caractère obligatoire à quoi que ce soit, on ne peut pas faire plus simple.

I ran four Drake 4 Series lines for six years in the 60's on autostart RTTY.  The stations ran 24/7, and transmissions (at full power) of 30 minutes or more were not uncommon.
Each transmitter had a small fan mounted on the back of the final cage.  The receivers had no extra cooling, but were NOT mounted under a shelf.  The receivers were crystal controlled and controlled the transmitters. The only  time the transmitters were turned off was for final replacement, which was done when the output power dropped to 100W on 20M. 
Only one failure  occurred during this time.  A single 12BY7 filament opened up. Power was supplied by TVA, at approx 1.5 cents/kwh.  Turn-on surge to cold tube filaments, transformer windings and mechanical power switch contacts are the most common problems when turning equipment on and off.  With the exception of tube filaments, none are easy or inexpensive to repair.  
 
 

Transformers are expensive, and back-of-pot switches are nearly impossible to find.  I switch most units with external power switches and internal switches are operated after external power has been removed. That said, I use my station every day, and leave the receiver on all the time.  I turn the transmitter on when I plan to transmit, and then don't turn it off until the end of the day.  When I leave town for a few days, I turn the receivers off.
A lot of my equipment has been modified with thermistor type surge protectors.  I learned this a LONG time ago when my little clock radio from Motorola had a similar device in it called a "Globar" resistor.  That radio came on five days a week for over 25 years, and never had a tube fail!  It wasn't on long, typically less than 10-15 minutes a day.

Just my experience.

73, Garey - K4OAH
Atlanta

Bonsoir Denis,
Je viens de terminer qq mods pour la réception des TR7 et R4C. Suite aux mods/idées et mesures du grand maître W8JI, etc.. j'ai réalisé qq
améliorations en essayant de rester dans la philosophie Drake sur les
versions 18K et 22K...La suite ici...

Marc vient de me faire parvenir un fichier dans lequel il décrit l'ensemble des améliorations/modifications qu'il a apporté à son TR7. Le fichier est téléchargeable depuis la page "Modifications"

Je viens d'ouvrir trois AC4 pour nettoyage d'été et j'ai mesuré machinalement les résistances d'équilibrage des diodes (330K)... La suite dans rubrique dépannage

J'avais constaté une erreur dans le manuel de maintenance du R7 concernant le réglage du seuil de la CAG, voici la solution trouvée sur
internet.

Daniel F6DAN a modifié sa ligne 4B en profondeur. il a eu la gentillesse de nous fournir toute sa documentation, c'est un travail colossal et certainement très fructueux. Merci Daniel
Toute la documentation accessible ici ou depuis la page "Les modifications"

F6EBB a réalisé un fichier PDF de grande qualité de la documentation de maintenance du R7. Cette documentation peut être diffusée par mail dans un premier temps. Eu égard au volume de données, il est possible de l'obtenir sous la forme de 5 fichiers   (4 MO) ou en un seul envoi de +/- 20 MO.

Pour l'obtenir en faire la demande à f6crp ou f6ebb
ou

Transceiver Designer Michael F. Elliott, W8KRR, SK (Apr 20, 2006) -- The man behind the development of the Heathkit SB-104 and Drake TR-7 transceivers, Michael Elliott, W8KRR, 66, of Centerville, Ohio, died April 14. Elliott received his BS in Electrical Engineering from Northwestern University in 1963. He went on to figure greatly in the development of the Heathkit
SB-104. Released in 1974, it was the first transceiver to incorporate solid-state design, come with a digital frequency readout and be priced for the mass market. The SB-104 was a mainstay until 1982, when radios that covered the new WARC bands superseded it. It was one of the last Amateur Radio kits that Heathkit developed. Elliott was also influential in the design of the Drake TR-7. This transceiver was the standard for competition-grade transceivers in the late 1970s and early 1980s. In his 1979 QST Product Review, David Sumner, K1ZZ, called the TR-7, "...the most convenient this reviewer has ever used. The styling is functional, and is similar to that used in  modern, high-fidelity audio equipment." Even today, he calls it "the breakthrough radio of its time." The two transceivers represented state-of-the-art technology from two American manufacturers.