Tuning toko rotary

ESSAYÉ EN FM ET LW OK POUR LES AUTRES BANDES PAS D’ANTENNES APPROPRIÉES Année: 1976-1978? Catégorie: Récepteur de diffusion - ou passé tuner WW2 Semi-conducteurs (le compte est seulement pour des transistors) 34: Superhétérodyne, conversion double / triple; IF / IF 2000/455 kHz bandes onde Diffusion, grande longueur d'onde, morethan 2 x SW, plus FM ou UHF. détails Type de puissance et de tension Ligne / piles (tout type) / 110/220 Volt Haut-parleur aimant permanent (Dynamic Pdyn) Haut-parleur (à bobine mobile) / 4 de pouce de diamètre = 10,2 cm out Power 2 W (qualité inconnue) de Radiomuseum.org Modèle: RF-4800 LBS / DR-48 - Panasonic, Matsushita, matière divers matériaux forme Modèle de table, profil bas (grande taille). Dimensions (LHP) 480 x 200 x 355 mm / 18,9 x 7,9 x 14 pouces notes Couverture LW, BC (MW), SW 1600-30000 kHz, VHF (FM). Dessous de 3000 kHz seule conversion, au-dessus de 3000 kHz à double conversion. Compteur numérique uniquement pour les bandes 2 ondes courtes - 8. Vendu aux États - Unis en tant que RF-4800 celui ci contrairement au DR 48 ne couvre pas le pas LW). Poids net (2,2 lb = 1 kg) 8 kg / 17 lb 9,9 oz (17.621 lb) The Panasonic RF-4800 LBS has been sold in Europe as DR-48, it covers also the longwave band. The DR-48 is a quite bulky desktop receiver with it's dimensions of 48 x 20, x 35,5 cm and it's weight of 8 kg; two metal handles give protection to the front panel, when the set is turned face down - the give the set the aspect of a semiprofessional receiver. The RF-4800 can be powered from 110 / 220 V mains, from a 12 V car battery or eight UM-1 / mono cells accomodated in two battery compartments. At the left side of the frontpanel, You find the big speaker and below the mains switch, the jacks for an external speaker and a cassette recorder at further right the rotary controls for volume, bass, treble and the BFO pitch control. In the middle of the display window at the right, You find the red LED display of the frequency counter active on shortwave bands SW 2 - 7 and the auxiliary dials for long-, mediumwaves, tropical bands (SW 1) and the FM broadcast band at the left and the shortwave bands SW 2 - 7, each 4 MHz wide, at the right. In the middle of the frontpanel the huge main tuning knob is located, it is equipped with a crank and can be set to slow and fast tuning speed by pressing the knob in the centre - this knob will tune the shortwave bands. The frequency display is active on these band segments and the receiver operates as a double conversion receiver. The second smaller tuning knob tunes the long-, mediumwave, SW1 and FM broadcast bands, in these bands, the set operates as single conversion set and the frequency display is not active. The signal strength meter tends to read high, in the RF-4800 it has a white background, this is a possibility to distinguish the set from the RF-4900, the S meter of the successor comes with a black background. Below You find a row of switches: the switch to activate the AFC in FM mode selects between the two AM bandwidths in AM mode, the middle switch activates the noise limiter and the third one the BFO: use the BFO pitch control just below for an optimum BFO note when receiving CW transmissions and for optimum speech reproduction in SSB mode - voices should no sound like mickey mouse. The bandswitch for LW - MW - SW1 - FM and the band segment switch for SW 2 - 7 are located below the right auxilitary frequency dial. The frequency counter can be calibrated from a 5 or 10 MHz time signal and frequency standard transmission from WWV / WWVH or even from another station transmitting exactly on a known frequency. Tune in to "Radio Deutsche" Welle on 6075 kHz and wait for news and station identification, then tune to maximum S meter reading and use the SW 2-7 CAL control to set the frequency display exactly to display 6.075 - with this control not set correctly, the frequency displayed can be 2 - 4 kHz off the actual frequency. Keep in mind, the RF-4800 is no PLL synthesized set. In the right lower part of the front panel, You find the ANT TRIM to match an external antenna, the R.F. gain control. This should be set to maximum position or "DX" as a standard, in case of overloading of the receiver front end due to high signal level conditions in acrowded shortwave broadcast band wit ha long antenna, You can reduce the R.F. gain. In fact, this knob acts more like an attenuator as there is no switch to turn off the AGC (automated gain control) completely. Three more switches activate dial illumination, frequency display and set the S meter to indicate battery power. At the rear face of the DR-48 / RF-4800 LBS, You find the two folding out ferrite antennas for long- and mediumwaves, the international variant comes with only one ferrite antenna. Next to the antenna sockets, there is a PL / SO 239 antenna socket for SW 2 - 7. The DIN socket can be used to feed the DR-48's audio signal to a cassette recorder and also to feed a signal from an external audio source to the receiver, set the switch at the rear to "PHONO" to use the DR-48 as audio amplifier. The operation scheme of the DR-48 is quite straightforward: turn on the set, make sure the RF gain control is turned to the MAX setting, the AM bandwidth to wide and the BFO turned off. The right bandselector should be on SW 2 - 7 and the left on "2" to select the 3 - 7 MHz range, the use the big tuning knob to find the "Deutsche Welle" from Cologne on 6.075 MHz. If the signal peak is one or two kHz higher or lower then 6.075, use the SW 2-7 CAL to adjust the frequency display setting to the correct frequency. Due to it's conventional design as a double conversion receiver with a quite low first I.F. and a frequency counter, the receiver shows a certain frequency drift even after warm up, CW or radioteletype decoding with an automatic decoder and even reception of SSB signals need slight retuning of the set from time to time, automated recordings won't work properly. The skirt selectivity of the two I.F. filter's is mediocre. quite often, You hear an 5 kHz interference whistle from a adjacent channel carrier. As the receiver operates as single conversion set below 3 MHz, You might encounter mirroring or "ghost signals" appearing 900 kHz from the original signal away. As the internal ferrite antennas cannot be switched of, the DR-48 / RF-4800 is not well suited as a longwave / mediumwave DX receiver. Conclusion: the DR-48 / RF-4800 represents the state of the art from the early eighties as desktop receiver with double conversion circuitry connected to a frequency counter, stability, suppression on unwanted signals and selectivity of the I.F. filters is all below the expectations for a shortwave receiver in the 21st century. The DR-48 / RF-4800 looks very impressive and makes a decent secondary or entry level shortwave radio, for real Dxing, You would need a set with better filters, maybe a notch filter and passband tuning and a few memories to compare different frequencies. If You find a DR-48 / RF-4800 for a bargain price, get one, and You might have lot of fun with it. The technical built quality is not superior, so You might encounter some work until the receiver is running properly. In my sets, the wave band and shortwave band switches all did contact poorly and needed cleaning, as well as the AM narrow / wide switch and even the rotary volume and tone controls.

Recepteur à Main Large Bande - ICOM   [IC - RX7] Très bon Etat, Marche comme au 1er Jour   Un scanner portable nouvelle génération, couvrant les fréquences de 150 KHz à 1,3 GHz, en AM, FM et WFM. A peine plus gros qu'un téléphone portable, ce récepteur est doté d'une interface conviviale accessible par menu.  Livré avec sa Boite d'Origine, le chargeur avec Adapt pour 220v, Clip, Dragone ? 2 ANTENNES (origine et WSMA889) ... Fonctionnement en mode VFO Atténuateur et contrôle de gain RF... 30 dB (environ) d'atténuateur et de contrôle de gain RF sont intégrés Contrôleur CT-17, CI-V en option pour le contrôle à distance par PC Fonction d'accélération du cadran... Lorsque vous tournez rapidement le bouton d'accord, la vitesse d'accord augmente automatiquement Réglage de la pause de numérisation (2-20 secondes et maintenu) et reprise de la numérisation (0-5 secondes et maintien) Mise hors tension automatique (30/60/90/120 minutes) et mise sous tension automatique (30 minutes à 24 heures) Réglage de la police de caractères grande et petite Le sélecteur rotatif et les boutons haut / bas sont réversibles Fonctions d'ouverture automatique du squelch et du silencieux Fonction d'économie d'énergie https://www.icomuk.co.uk/ic-rx7/Handheld_Receiver-Scanner Wideband Handled Receiver  ICOM [IC-RX7]    Very good condition - Works as 1st Day A new generation scanner, covering frequencies from 150 KHz to 1.3 GHz, AM, FM and WFM. Barely bigger than a mobile phone, this receiver has a user-friendly menu-accessible interface. Comes with its Box of Origin, the charger with Adapt for 220v, Clip, Handstrap...& 2 Antennas: ORIGINAL &  Watson WSMA889... VFO mode operation Attenuator and RF gain control...30dB (approx.) of attenuator and RF gain control are built-in Optional CT-17, CI-V controller for PC remote control Dial speed up function...When rotating the tuning knob rapidly, the tuning speed automatically speeds up Scan pause setting (2–20 seconds and hold) and scan resume (0–5 seconds and hold) setting Auto power off (30/60/90/120 minutes) and auto power on (30 minutes to 24 hours) Large and small font setting Rotary selector and up/down buttons are reversible Auto squelch and squelch open functions Power save function