BROWNING UNIVERSAL FM - AM TUNERS - MODEL RJ - 20 AND MODEL RJ - 22

These tuners are designed to please the most discriminating listener. Truly high fidelity reception of F11 and All broadcasting has been engineered into these tuners which are specifically intended for custom receiving installations. The AM section features variable I., bandwidth with a broad high fidelity position and a narrow, interference reducing position. The FM section uses Major Armstrong's circuit and features dual limiters for best noise elimination. Bass and treble controls provide 20 db of boost at either end of the audio band and the associated audio amplifiers assure output commensurate with phonograph pickups. The power supply is self-contained and the chassis is styled for ease of mounting in bookshelves, cupboards, drawers and other confined locations,

INSTALLATION:
In mounting the unit, due consideration must be given to ventilation. Approximately 100 watts of heat must be dissipated. Position of mounting is not important.

If the speaker is to be located in or very near the cabinet in which the tuner is located, it may be necessary to shock mount the tuner on rubber or felt pads to entirely eliminate mechanical feedback.

The output of the tuner may be fed directly into the input of any high quality amplifier and speaker system. The gain of the amplifier should be such that 0.5 volt RMS will provide the desired output.

Antenna connections must be made as shown in the drawing " RJ - 20 Antenna Connections ". As may be seen, all ordinary possibilities have been foreseen and any good commercial FM antenna may be used. For those who wish to make their own antenna, the drawing " RJ - 20 antenna constructed of 300 ohm twin lead " is supplied. Careful adherence to this drawing will provide a very satisfactory antenna.

Shielded leads from the tuner to the amplifier and also from the phonograph pickup to the connectors at the rear of the chassis are essential. The two male connectors will be found plugged into the female chassis connectors in the RJ - 20 and several feet of shielded wire is packed with each tuner, It is advisable to make these leads as short as possible in order not to impair the high frequency response.
Since individual installations vary, this wire is supplied uncut.

When making up the cables, the center conductor should be stripped and tinned, inserted in the center sleeve of the connector and heated until the solder flows making a good joint. Bring the braid up on the outside shell of the plug and solder all the way around,

There are some cases where the shield braid on the lead between the audio output of the RJ - 20 and the amplifier employed may not be sufficient ground bond between the two. In cases where there is any hum (not present in the amplifier itself), try bonding the RJ - 20 chassis to the audio amplifier with heavy copper braid or number 16 or larger wire.

A panel layout of the RJ - 20 appears on the next page to facilitate cutting the panel to fit the unit. The shaft lengths are such that panel thickness up to 1/4 " may be used.

OPERATION:
After proper installation, the tuner may be put into operation by turning the ON - OFF switch clock wise; the dial should be immediately illuminated. Within a minute, the tuning eye should emit a bright green glow. The tuner is ready to operate 02 AM,
Allow two minutes warmup for FM CONTROLS:
1. ON - OFF switch - Power switch independent of controls so they may be left in any desired position.
2. VOLUME - Controls medio output from FM, AM, or PHONO source.
3. AM - UM - PHONO - Bandswitch which selects type of reception desired.
4. NARROW - BROAD - Controls bandwidth of the AM I.F. amplifier. BROAD position is for high fidelity reception of strong, clear stations. NARROW position for best reception of weak stations or in crowded portions of the band. When tuning AM stations always tune in NARROW position switching to BROAD after tuning is complete.
5. TUNING Selects stations on either FM or AM bands. Tune slowly and exactly using the tuning indicator as shown in drawing " RJ - 20 Tuning Eye ". Note: When tuning AM stations have NARROW BROAD switch in NARROW position. After correct tuning is achieved, turn switch to BROAD if desired.
6. TREBLE - Provides 20 db of treble boost in full clockwise position,
7. BASS - Provides 20 db of bass boost in full clockwise position.
For flat response, both BASS and TREBLE should be fully counterclockwise.

For those who wish to incorporate phonograph connection to the tuner, a phono input connector is provided at the rear of the chassis. By turning the selector switch to PHONO, the phonograph input is connected to the amplifier through the tone and volume controls of the tuner. Bass and treble content as well as volume can be controlled directly with the tuner knobs,

It should be noted that while tuning between stations, both on FM and AM, the rushing noise is normal for the tuner. The extremely high sensitivity is responsible for picking up random atmospherics, but this will be eliminated when a station is tuned in provided the signal exceeds the noise voltage at the, antenna.

ADJUSTMENT:
No adjustment should be made on the tuner aside from the panel controls. Adjustments and alignment on the FM portion should only be made by experienced personnel with the proper visual alignment equipment. Ordinary meters or aural methods are in general unsatisfactory for alignment. Replacement of tubes can usually be made without realignment.

RJ - 20 FM ANTENNA CONSTRUCTED OF 300 OHM TWIN LEAD

CONNECTIONS WHERE 300 OHM FM ANTENNA AND SEPARATE AM ANTENNA IS TO BE USED

CONNECTIONS FOR SEPARATE ANTENNAS WHERE 50 OR 72 OHM FM ANTENNA IS USED

NOTE: " IN CASES WHERE 300 OHM FM ANTENNA IS TO BE USED FOR BOTH FM AND AM RECEPTION, "

If 300 ohm twin lead from FM antenna to tuner is longer than about 25 ft., use con denser supplied as jumper. (This condenser is externally connected to the terminals when the tuner is received.)

CONNECTIONS WHERE 300 OHM FM ANTENNA IS TO BE USED FOR BOTH FM & AM RECEPTION RJ - 20 ANTENNA CONNECTIONS

INSTRUCTIONS FOR ALIGNMENT OF BROWNING MODELS RJ - 20 AND RJ - 22 FM - AM TUNER
Visual alignment of both FU and AM sections is to be preferred, but in case apparatus is not available, the following point-to-point method may be used. Visual alignment data are given in " DATA ON BROWNING MODEL RV - in FW TUNER which can be applied to the RJ - 20 and the RJ - 12A

EQUIPMENT EMPLOYED:
FN SECTION
a. Signal generator covering 8,200 to 8,300 KC. with a sufficiently large dial so that 25 KC, can be accurately read.
b. Signal Generator from 88 to 108 WC.
c. A DC vacuum tube voltmeter which has an input resistance of more than three megohms.

IF - FM ALIGNMENT Band Switch to FM Position,
1. Connect output of signal generator to ground and to pin # 8 of the 778 mixer oscillator tube. (This point is most conveniently reached by connection to the stater plates of the mid-section of the three gang variable mi condenser by see instructions on RJ - 20 for location of perts.) Set signal generator at 8,250 KC.
2. Connect vacuum tube voltmeter between ground and the lower end of the l. meg. resistor, A53.
3. Tune primary and secondary of first, second and third Fu IF transformers for substantially maximum limiter voltage as indicated by VTVN. Increase or decrease the output of the signal generator as required so that VTVU maximum reading is about 5 volts.
4. Set signal generator at 8,200 KC. The limiter voltage should be about the same as above (at 8,250 XC.)
5. Set signal generator at 8,300 KC. The limiter voltage should be about the same as at 8,250 KC.
6. If the FM IF response is not symmetrical, make adjustments on the FM IF transformers until a curve is obtained similar to that show in Fig. 4 in * DATA ON BROWNING HODEL RV - in FW TUNER ".

FN DISCRIMINATOR ALIGNMENT
7. Connect DC VTVM between ground and the terminal of the 1 meg. resistor (R50) which is connected to the condenser C45. Set VTV on 5 volt scale.
8. Connect signal generator as in No. 1. Set signal generator to 8,250 KC, and the output for about 5 volts on the limiter.
9. Adjust secondary of discriminator to zoro voltage on VTVU. Use insulated screwdriver. Changing the tuning of the discriminator secondary should give positive and negative voltages either side of zoro. Adjustment is critical.
10. Change signal generator from 8,200 to 8,300 KC., keeping signal voltage constant. Adjust primary of discriminator (800 instructions of RJ - 20 for location) so that equal and opposite voltages are developed.
11. Set signal generator at 8,250 KC, and check to see 1 VTVM reads zero as the primary adjustment may have changed the secondary. Readjust for zero

ALTERNATE METHOD OF ADJUSTING THE PRIMARY OF THE DISCRIMINATOR
10A, Connect VTVM between ground and the junction of R47 and R48. Set signal generator at 8,250 KC. Adjust primary of discriminator for maximum DC voltage as read by VTV.
11A, with signal generator set at 8,250 KC, and VTVM connected between ground and junction of R50 and C45, check to see that secondary of. the discriminator transformer is tuned so that VTVM reads zero,

ADJUSTMENTS OF FM OSCILLATOR, RF, AND MIXER CIRCUITS
12. Feed a signal of about 105 MC, from a signal generator to the antenna of the receiver, With the VTVM connected between ground and the lower end of the 1. meg. resistor (R53), see if the oscillator frequency is so got that the dial reading is in accordance with the received frequency; that is, maximum VTVM reading should be obtained when receiver dial is set at the same frequency as the signal generator. If not, adjust padder (see RJ - 20 Instructions for position) slightly so that frequencies marked on dial correspond to that of the signal generator (it is assumed that the signal generator is on frequency this can be checked with FH stations.)
13. Adjust RF and mixer (for location see RJ - 20 Tube Layout) trimmers for maximum reading. The RF stage will be found to be much broader than the mixer which is relatively sharp.

AM SECTION

EQUIPMENT EMPLOYED.
Signal generator covering 465 KC, and frequencies from 500 to 1600 KC. ba A DC vacuum tube voltmeter which has an input resistance of more than three megohms.

IF - AN ALIGNMENT Band Switch to AM Position.
14. Set " Broad * Narrow Switch to " Narror " (position counter-clock wise).
15. Connect signal generator between ground and pin 8 of 6SA ? (this point is most conveniently reached by connecting to the stater plates of the middle section of the three gang AM tuning condenser) Set signal generator to 465 KC.
16. Connect VTVM between ground and the lower end of R16 ( 2 meg. resistor for AVC).
17. Adjust AM - IF transformers for maximum response. It will be found that the adjustment of T2 is quite sharp. T3 is much broader.
18. Switch " Broad " - " Narrow * switch to " Broad " position. Change signal generator 3. KC, either side of 465. KC., from 462. to 468 KC, Observe VTVN reading as signal is changed. The F response should be nearly symmetrical with two peaks and a small valley between then, If not, slight adjustments may be made on T3.
19. Switch to " Narrow " position and set signal at 465 KC, and see a sharp resonance curve has been altered. If necessary, peak again by adjustments on T2. Successive adjustments of is and is may be required. If visual method is used, observation makes adjustments relatively easy.

ADJUSTMENTS OF AN OSCILLATOR, RF, AND MIXER CIRCUITS
20. Feed a signal from signal generator into the AM antenna, Set signal generator at 1300 KC. With VTVM connected on AVC circuit as per 16, set oscillator trinnor, if necessary, so that dial roads 1,300 KC, when Maximum response is obtained,
21. Sot signal generator at 1400 KC, and adjust RF and aixor trimmers for maximum responso. Keep signal low enough so AVC voltage will not exceed 3 or 4 volts.
22. Set signal generator to about 600 KC. Adjust AN padder for maximum response by changing the frequency from signal generator a few KC. either way and observing VTVN.

RJ - 20 FM - AM TUNER

RU - 20 CONTROL LAYOUT

RJ - 20 REAR VIEW

RJ - 20 TUBE LAYOUT

RJ - 20 PANEL LAYOUT

RJ - 20 TUNING EYE