|
| |
|
Picture : RL DRAKE TR-7 User Manual
|
| The TR-7 is a
solid-state, broadband, SSB/CW transceiver which covers all amateur bands
from 160 through 10 meters. The TR-7 offers excellent sensitivity and
selectivity, high dynamic range, digital frequency readout and full
break-in CW operation.
A front panel switch allows the operator to
Select an optional crystal filter independent of the MODE switch. A wide
range of optional crystal filter band-widths are available, and
installation of an accessory filter can be accomplished in minutes. The
standard bandwidth is 2.3 kHz, and it is automatically selected in
transmit to insure proper signal characteristics. A passive double
balanced mixer is employed in the receiver front end. This stage is
preceded by a low noise, high dynamic range bipolar rf amplifier to
provide good strong signal performance and weak signal sensitivity.
The digital frequency readout of the TR-7
is derived from a true frequency counter to assure an accurate display of
operating frequency. In addition, the tuning knob dial skirt is calibrated
in 1 kHz increments to facilitate short frequency excursions.
The transmitter of the TR-7 features a
rugged, solid-state power amplifier section which has been de-signed for
continuous duty in the SSB and CW modes. For more demanding duty cycles,
such as SSTV or RTTY, the Model FA-7 cooling fan is available. The
transmitter section also features very low harmonic and spurious output,
and is equipped with automatic high VSWR protection.
The VOX GAIN and DELAY controls are
conveniently located on the front panel, and full break-in CW operation is
obtained via a switch on the VOX DELAY control. VOX operation can be
disabled by a front panel switch.
Other features include selectable AGC time
constants, receiver incremental tuning (RIT), provision for an accessory
noise blanker (NB-7), and T/R switching connections for an external linear
amplifier and/or receiver.
The modular construction of the TR-7
reduces service time to a minimum. Each module is designed to perform a
specific function, and this feature, combined with the open, accessible
layout of the transceiver greatly simplifies any required alignment and
troubleshooting. Liberal use is made of table connectors, simplifying
module removal.
Prototype : TR7
transceiver, army green, for 19" rack mounting
|
GENERAL :
 | Frequency Coverage: 1.8-2.0*, 3.5-4.0,
7.0-7.5,10.0-10.5, 14.0-14.5, 18.0- 18.5*, 21.0-21.5, 24.5- 25.0*,
28.0-28.5*, 28.5- 29.0, 29.0-29.7* MHz.(*With accessory range
crystal). |
| Modes of Operation: U SB, LSB, CW |
| Frequency Stability: Less than 1 kHz
drift first hour. Less than 150 Hz per hour drift after first hour.
Less than 100 Hz change for a * 10% line voltage change. |
| Readout Accuracy: * 10 ppm * 100 Hz |
| Power Requirements: 13.6 VDC regulated,
2 A. 12 / 16 VDC unregulated, 0.8 V rms maximum ripple, 15 A. |
| Dimensions: Depth: 12.5 in. (31.75 cm),
excluding knobs and connectors. Width: 13.6 in. (34.6 cm). Height: 4.6
in. (11.7 cm) excluding feet. Weight: 14 lb. (6.35 kg)
|
TRANSMIT :
| Power Input (Nominal): 150 Watts, PEP or
CW |
| Load Impedance: 50 ohms. |
| Spurious and Greater than 40 dB |
| Harmonic Output: down. |
| Inter-modulation Greater than 30 dB |
| Distortion: below PEP. |
| Carrier Suppression: Greater than 50 dB. |
| Undesired Sideband Greater than 60 dB at |
| Suppression: 1 kHz. |
| Duty Cycle: SSB, CW: Key Down ( w/o FA7
Fan): 100% 30%, 5 minutes maximum transmit |
| Key down (w/FA7 Fan): 100% |
| Microphone Input: High Impedance |
| CW Keying: Instantaneous full break-in,
adjustable delay.
|
RECEIVE :
| Sensitivity: Less than 0.5 uV for 10 dB
S+N/N except less than 1.0 u V 1.8-2.0 MHz. |
| Selectivity: 2.3 kHz minimum at –6 dB.
4.1 kHz maximum at –60 dB. (1.8:1 shape factor) |
| Ultimate Selectivity: Greater than 95
dB. |
| AGC : Less than 5 dB output
variation for 100 dB input signal change, referenced to AGC threshold. |
| Inter modulation: (20 kHz or greater
spacing) |
| Intercept Point: Greater than 0 dBm. |
| Two-Tone Dynamicn Range: Greater than 85
dB. |
| IF Frequency: 5.645 MHz |
| IF Rejection: 50 dB, minimum. |
| Image Rejection: 60 dB, minimum below 14
MHz. 50 dB, minimum above 14 MHz. |
| Audio Output: 2 watts, minimum @ less
than 10% THD (4 ohm load). |
| Spurious Response: Greater than 60 dB
down.
|
Two
different 2nd IF / Audio board ?
|
QUESTION
My TR-7 has a different 2nd IF/Audio board than what is shown in the
service manual. Mine has a MC1496 double balanced Mixer chip
used as the product detector |
The service manual shows
a schematic for a standard diode product detector. Now the question is
which of these two were the original and why did they make the
change??
I would guess that the one that is the latest design turned out to be
better??
steve
|
ANSWER
The original was the diode product
detector.
In the service manual from 1978 they have the diode product detector.
In the update one, (with a text saying "reprinted with revisions
October, 1980") the diode product detector board is called
version 1, and the MC1496 is called version 2.
The TR4310 transceiver has the version 2 2nd IF/Audio board. Both the
R7, (both in the original service manual from 1979, and the updated
from 1980) and the R4245, has a MC1496 product detector.
My thinking as that they concluded that the MC1496 was the better one,
when designing the R7, and then implemented this in the TR7, and also
the TR4310 and R4245.
73 de Lars, SM6RPZ
Lars E Pettersson
Chalmers University of Technology
Gothenburg, SWEDEN
d8lars@dtek.chalmers.se |
|
ACCESSORIES for
TR-7
| AUX-7 Auxiliary
program board, Model 1536 |
| DR-7 Digital
readout |
| MMK-7
Model 1335 Mobile Mounting Kit |
| MS-7
External Speaker, Model 1531 |
| RV-7 Remote
VFO for TR-7- RV-75 Synthesized
Remote VFO’s. Permit rcvg, xmtg or xcvg on separate frequency in
same band as xcvr |
| PS-75
& PS-7 Power Supply, Model 1545 |
| MN-75 & MN-7
antenna matching network, Model 1540 |
| NB-7
Noise Blanker |
| FA-7
Cooling fan, Model 1529 |
| Desk Microphone,
Model 7077 ( Astatic ) |
| SP-75 Speech
Processor, Model 1553 |
| CW-75
Electronic Keyer, Model 1507 |
| P-75 Phone Patch,
Model 1520 |
| Crystal filters |
 Drake
TR-7 HF Transceiver (Product Review)
(c) QST 05/1979 - page 37 - 111 Kb file - Adobe
pdf version
|
  
|