Modifications for the Uniden HR2510

19-07-1998 HR2510 - Lincoln Web site English language (0 Kbytes)
19-07-1998 Tips and trick for the HR2510 English language (18 Kbytes)
19-07-1998 Information on the HR2510 10 meter radio English language (1 Kbytes)
19-07-1998 Expanded frequency coverage for the Uniden HR2510 English language (2 Kbytes)
19-07-1998 Speed up the AGC for Uniden HR2510 English language (3 Kbytes)
19-07-1998 Output power mod for the Uniden HR2510 & HR2600 English language (3 Kbytes)
19-07-1998 HR2510 RIT-control mods English language (2 Kbytes)
03-01-1999 Adding 24-26 MHz to the HR2510 & 2600 English language (3 Kbytes)
20-10-2001 Frequency modification: President/Uniden HR-2510 English language (6 Kbytes)
20-10-2001 HR2510 Modification for increased MicGain English language (7 Kbytes)
20-10-2001 President or Uniden HR-2510 Variable Power Modification English language (8 Kbytes)
20-10-2001 Increasing the power output for the HR2510 or Lincoln English language (11 Kbytes)
20-10-2001 HR2510 Hi-Power modification (Better and easier) English language (17 Kbytes)
20-10-2001 Modification of the HR2510 Mic buttons to operate the VFO English language (18 Kbytes)
20-10-2001 Talkback removal English language
20-10-2001 HR2510 RIT / Clarifier Mods English language (4 Kbytes)
20-10-2001 HR2510 Misc. Enhancements English language (6 Kbytes)
20-10-2001 24 MHz Broadband instructions for your HR2510 English language (9 Kbytes)
20-10-2001 HR2510 Alignment Instructions English language (18 Kbytes)
 View all modification in one click. This can be a very big file.!! (151 Kbytes)

20-10-2001
Talkback removal
Author: VE2XQQ


MOD #1 - The Relay Approach

One method of Talkback removal is to break the speaker line with a relay.

Parts needed :

12Volt SPDT relay
2 - 1N4148 Diodes
1 - 1N4001 Diode
Several pieces of hookup wire

Jumper the Relay coil - K1 with a 1N4001 Diode - D1. To key the relay you connect one side of the Relay coil (the side with the Cathode of the diode) to IC107 pin 1.(HA17808W)

Cut the Blue wire that goes to pin 1 of the AUX plug on the rear of the radio. (Make sure you leave enough wire to reconnect each end to wires for the relay.) Attach the wire from pin 1 of the AUX plug to the Wiper contact of the Relay- K1. Attach the other half of the Blue wire to the Normally Closed side of the Relay.

(Make sure you leave enough wire to reconnect each end to wires for the relay.)

Cut the Yellow wire from pin 3 of the Mic plug. Jumper the cut Yellow wire with a 1N4148 Diode - D2 (Cathode to the Mic Plug Pin 3) Connect the last 1N 4148 Diode - D3 to the Relay coil, Anode side to the Anode of the Diode - D1 on the coil of the relay.Connect the Cathode to Pin 3 of the Mic plug.(Cathode to Cathode of the two diodes on pin 3 of the Mic plug.)

MOD #2 - The Solid State Approach I

All that is needed is to add a 1N914 Diode from pin 6 of IC103 to the collector of Q125.

Connect the cathode of the diode to pin 6 of IC103, and the anode to the collector (the center pin) of Q125.

MOD #3 - The Solid State Approach II

All that is needed is to add a 1N914 or a 1N4148 Diode connected to a 10k to 100k resistor from pin 6 of IC103 to the Base of Q127.

Connect the anode of the diode to one side of the resistor. Connect the other side of the resistor to pin 6 of IC103, and the cathode to the Base of Q127.

Note: Use a 10k ohm resistor if you only use the internal speaker. Use a 100k ohm resistor if you use an external speaker.

These last 2 MODs remedies the Audio Feedback caused by the Audio Amplifier chip, IC103 (TDA 1905) not being switched over completely from RX to TX when you key the mike. These fixes rebias the switiching transistor to correct this.

Thanks toVE2XQQ for the mods and schematic.

This modification is read 182 times.

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