February 4, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-1 Blowing RF Fuse in Alignment Generator + + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------- February 14, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-2 Low Power Output + + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- March 7, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-3 Troubleshooting Low Sensitivity+ + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- March 16, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-4 Synthesizer Lock Instability + + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- March 16, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-5 Power Drops Off When Installed in Case + + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------- May 25, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-6 Units Fails to Lock Until 0-5 kHz Switch is Actuated + + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------ May 25, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-7 Crystal Check+ + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------- July 8, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-8 Improve IF Response+ + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------ July 11, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-9 Synth Goes Out of Lock at Anything Over a Low-Listening Level + + + + Information not yet available + + + + ------------------------------------------------------------------------------------------------------------------- July 27, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-10 Conducted Spurious Modification+ + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- September 14, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-11 L201 Tuning Peak at Bottom of Coil + + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- September 21, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-12 Sync Won't Lock, No TX + + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- November 17, 1977HW-2036 BulletinNo:2-Meter Transceiver HW-2036-13 High Internal Spurious Levels in Receiver + + + + Information not yet available + + + + -------------------------------------------------------------------------------------------------------------------- March 14, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-14 Reduce Receiver Spurs and Reference Tone in Transmit The following changes are recommended to reduce receiver spurs and objectionable levels of 833 Hz reference tone in transmit signal. You maynot notice a significant reduction in the reference tone level if it is already low. The "mod" will reduce the objectionable levels approximately 10 dB.Parts Required: 1 ea #8 solder lug [PN 2959-24] 1 ea #6 solder lug [PN 259-1] 1 ea 100 pF capacitor [PN 21-75] 2-1/2" Small red stranded wire [PN 344-90] 3/4" Small sleeving [PN 346-1] Transmitter Board:- Change C403 from .001 uF to 100 pF [PN 21-75]. - Remove the red wire and one lead of C2 [.001 uF] from point S. Save thetwo ferrite beads from the lead of C2.- Remove C2 and discard. - Solder PCB pins B, L and N to the foil on the TOP side of the Transmitter board. - Splice the 2-1/2" red stranded wire onto the red wire that was removedfrom point S. Place sleeving over the splice. - Connect the red wire to the OUT PCB pin. Wrap the end of the wirearound the top of the pin and solder.Power Amplifier Board - Prepare the #8 solder lug [PN 259-24] (At 9/16" bend the eyelet end of the solder lug at a 90 deg angle. Then cut off the end 1/2" from thebend.] - Mount the #8 solder lug and the #6 solder lug at point X, as shown. //The #8 solder lug is shown connected to the chassis with following sequene: washer, #8 lug, #6 lug, nut. The bent 'foot' of #8 is then soldered to the chassis.//- Solder the #8 solder lug to the chassis. - Remove the shield lead of the coax cable at point B on the Power Amplifier board. Then solder this shield lead to the #6 solder lug at point X.NOTE: When checking receiver spur levels, a 50 ohm impedance must be connected to the antenna input jack. ------------------------------------------------------------------------------------------------------------------- April 14, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-15 No VCO Lock (Temperature Related) QA has looked into this problem and has determined that NPC or NP devices should NOT be used for Q501, Q503 or Q401. All other manufacturers of Part # 417-801's are acceptable replacements. (NPC or NP devices are clearly marked; factory parts inventory does not contain NPC devices). ----------------------------------------------------------------------------------------------------------------- May 30, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-16 Wrong Diode Installed At VD-502 Diode VD-502, on the VCO circuit board, should be an MV-2110 [PN 56-640]. This diode is packed in a special bag marked "HW-2036A". The MV-2107 is packed with the VCO parts and may have been used at this location. Also check R302 on the Power Amplifier circuit board. This resistor should be a 100 K ohm, 5 % [PN 6-104-12], instead of a 10 %. -------------------------------------------------------------------------------------------------------------------- July 24, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-17 Receiver Spurs On Repeater Frequencies A number of receier spurs are present in the HW-2036 and HW-2036A. When the 10 MHz and 21.55 MHz oscillators are correctly set per the manual, several of these spurs will occur on standard repeater channels, i.e.,147 MHz. These spurs may be moved off channel by adjusting the 10 MHz oscillator high or low by some [change of] f, and compsensating at the center of the band by readjusting the offset oscillators (receiver and transmit). The spurs will move approximately 1500 Hz for every 100 Hz [change of] f, and in the same direction as [change of] f. For example, if the 10 MHz oscillator is set 500 Hz high, the spur at 147 MHz will move up to 147.0075 MHz. The offset oscillators must be adjusted in the opposite direction by 0.1 [change of] f for the HW-2036A, or by 0.117 [change of] f for the HW-2036. (The offset oscillator does not affect spurfrequencies.) The price to be paid is a frequency error, which will be maximum at the band edges. This maximum error will be 1/5 [change of] f in the HW-2036A, and 1/10 [change of] f in the HW-2036. For example, if [change of] f = 1 kHz, maximum error = 200 Hz in the HW-2036A, 100 Hz in the HW-2036. This is less than 0.00015% or 1/10 of the stability specification, and should be an acceptable trade-off to a customer bothered by a spur.The procedure is as follows: 1. Tune to the offending spur. 2. With dummy load attached, adjust the 10 MHz oscillator justenough to drop the spur to an acceptable level. 3. Set switches to center of band. 4. Adjust offsets by following one of the procedures in themanual. 5. Check to see that no spurs have moved onto other desiredchannels. ------------------------------------------------------------------------------------------------------------------- July 24, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-18 No FM Quieting If there is no FM quieting, although deviation can be heard at .5 uV and signal strength meter deflects normally, check: IC502, the VCO oscillator chip [PN 443-740]. It may be noisy, causing high noise injection at the first receiver mixerstage. ------------------------------------------------------------------------------------------------------------------- July 24, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-19 PLL Will Not Lock; Cannot Adjust TP401 to 2.2 Volts Some early "A" models were shipped with incorrect VCO coils and incorrect capacitors for C509 and C513. If the VCO test voltage at TP401 changes rapidly between .5 and 4.5 volts, check these components, The correct parts are: VCO coil, blue [PN 49-1855] C509; 22 pF capacitor [PN 20-99] C513; 125 pF capacitor [PN 20-177] -------------------------------------------------------------------------------------------------------------------- September 26, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-20 Synthesizer Circuit Board [PN 85-1877-4] Screening InconsistenciesNote the following screening errors: Component Location Correct Value Value Screened on Board ----------------------------- ------------------- ------------------------------------ R447 820 Ohm 470R445 2200 Ohm 6800C403 100 pF ceramic .001 ---------------------------------------------------------------------------------------------------------------- October 11, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-21 Low Power Output After the unit has been operating for a period of time, L106 and L107 may not tune properly and there will be low RF voltage at T1, along with low power output. The center conducter of J102 on the transmitter circuit board may be cutting the insulator paper below the circuit board (on the chassis) thus shorting the RF to ground. If the lower washers on the board mounting studs are missing, the board will rest too close to the chassis, which causes the jack to come in contact with the chassis and insulator paper, eventually shorting to thechassis. Be sure the lockwashers are properly installed and if need be, the center lug of J102 may be trimmed slightly to provide additional clearance. ------------------------------------------------------------------------------------------------------------------ November 20, 1978HW-2036 BulletinNo:2-Meter Transceiver HW-2036-22 Part # 417-240 FET's Supplied With Shorting Wire On Leads This unit may have been shiped with a shorting wire around the leads of the Part # 417-240 device. The manual does not give instructions to the customer for the removal of this shorting wire. When servicing this product, check for the possibility of the shorting wire still installed on this device. The manual is being inserted with the proper instructions concerning the removal of the shorting wire. ------------------------------------------------------------------------------------------------------------------ January 9, 1979HW-2036 BulletinNo:2-Meter Transceiver HW-2036-23 Relative Receive Signal Strength Meter Inoperative But Receiver Sensitivity Meets Specifications Q204 [PN 417-169] is defective. Typical meter operation is 2 -5 uV for full scale deflection. ------------------------------------------------------------------------------------------------------------------- February 16, 1979HW-2036 BulletinNo:2-Meter Transceiver HW-2036-24 Pilot Lamp Holder Interferes With Removal And Installation Of VCO Cover The pilot lam