					March 23, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-30

		     Spurious Responses on Ten Meters

Some of the high level spurious responses found on ten meters is due to the
high VFO injection which occurs when the VFO attenuator pad is bypassed on
transmit.  This should be corrected in all SB-104's received for service by
clipping out the 1000 ohm resistor at R1251.

This change keeps the attenuator pad and VFO filter in the circuit at all
band switch settings by disabling switch transistor Q1251.

In addition to this change, put four large ferrite beads [PN 475-12] on the
grey lead from chassis connector pin K5 to lug 8 of the relay.  Glue
ferrite beads to chassis with PN 350-12.
-----------------------------------------------------------------------------
--------------------------------------
					March 24, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-31

			                       Improved Sensitivity

The following change should be made to all SB-104's received for service:

	Remove and discard	L733
	Remove and discard	C787

This change eliminates the series resonant circuit from the colector of
Q703 to ground, and improves the performance of the PN 40-1875 coil at
L734.
-----------------------------------------------------------------------------
---------------------------------------
					March 24, 1976
SB-104									Bulletin No:
Solid State Transceiver							SB-104-32

		                              Improved +11 Volt Regulation

The 680 oh, 5% resistor at R254 [See Bulletin No. SB-104-12] may not work
well in all cases.  When the +11 volt buss is found to be low, R254 should
be replaced with a 750 ohm, 5% resistor [PN 1-96].

This bulletin does not apply to the HW-104, since all production units have
the 750 ohm resistor installed at R254.
-----------------------------------------------------------------------------
---------------------------------------
					April 9, 1976
SB-104/HW-104								Bulletin No:
Solid State Transceiver							SB-104-33

		                                 Product Improvements

Low Power On All Bands

Select R-332 with a D.V.M. to 1.2K 1% or slightly higher.  Future runs will
use a 1% resistor.  The part when speced in will be assigned a new number. 
Keep in mind, the power spec is 80-125 watts.  Too much power can cause
additional problems. An ideal performance would be 100 W on all bands.

Carrier Suppression

Carrier  suppression can be improved, if there's ample power on all bands,
by lowering the value of R314[1K] to as low as 390 ohm.

The carrier balance adjustment can be accurately made by watching the "S"
meter on another receiver tune to frequency and adjusting for minimum
reading.  Couple the receive antenna to the SB-104 to provide an adequate
reading.  Also, see Bulletin No. SB-104-19.

Unstable And Excessive Harmonic And Spurs 15 & 10 Meters

	ALC Board

	If the SB-104 has been oscillating for some reason, theres a possibility
coils L801, L802 and L803 have been overheating.  There will be no physical
sign of this now.  Direct replacement cures the problem.

	Driver Board

	The Driver Board mounting holes (3) do not have the solder resist cleared
for secure grounding when the hardware is installed.  Each board must be
disassembled, solder resist cleaned from around the holes, tinned and
reassembled.  If the transistors have been oscillating on this board they
will probably be getting hot as a sign now.  They must be replaced.

	C Board

	When first keyed a spur occurs due to late ALC action.  Remove C322 on ALL
SB-104's serviced.

	If one band has more output than others and you suspect spurs, change any
one [or more] of the corresponding output resistors R337, R339, R343 or
R345 to 100 ohms [PN1-1-12].  The most likely one is 40 meter R343.

	Chassis

	The four ferrite beads in Bulletin No. SB3-104-30 should be cemented down
with the same cement used for the coils [PN 350-12].  This is for
mechanical reason only.

Low Sensitivity

	G Board

	To improve the 80 meter sensitivity, change L734 to PN 40-1726.  Remove 2
turns before installing this coil.  Future runs will have a coil for this
location with its own part number.  When it's available, you will be
advised.

	In the first 3 runs, the coils were not color coded.  We also find, many
of these coils in the B,P,F,S, are below Q spec.  If you have a sensitivity
problem change to the new number.  80 to 10 meters is usually the more
difficult ones to meet spec.

		New 10 M coil [PN 40-1875 (Red)]
		New 80 and 40 M coils [PN 40-1882 (White)]

	The new numbers are found in the most recent manuals.  Also a cross
reference is in the HW-104 service data book.  Also suspect the (3) 8.65
MHz B.P.F. coils [PN 40-1805].

	E Board

	Remove R613

	Change R619 from 560 ohms to 100 ohm [PN 1-1-12].
-----------------------------------------------------------------------------
----------------------------------------
					April 21, 1976
SB-104/HW-104								Bulletin No:
Solid State Transceiver							SB-104-34

		                        Trimmer Capacitors Tune Full Open

The 40M and 15M bandpass filter trimmers C718 and C741 usually trim fully
open, preventing proper tuning of the filter and reducing sensitivity. 
Make the following changes in all SB-104/HW-104's received for service.

	Change:	C719	30 pF s.m.	to 24 pF s.m. [PN 20-77]
	Remove and Discard C742 3.9 pF disc.

The capacitor plates in the square black trimmers are indicated by the
indented and raised spots on the capacitor body -- the capacitor is fully
meshed when the indented and raised spots are closest to each other.
-----------------------------------------------------------------------------
-------------------------------------
					April 21, 1976
SB-104/HW-104								Bulletin No:
Solid State Transceiver							SB-104-35

	                          Low Sensitivity On 10M and 15M, Other Bands OK

In cases of reduced sensitivity, bypassing the 8.65 MHz band reject filter
located under the chassis should result in an increase of not more than 1
db on 10M and 15M.  Check the series and shunt torroids by pulling them
slightly away from the terminal strip and re-checking the filter
attenuation.  A noticeable improvement in signal-to-noise ratio indicates
the insulating formvar on the torroid windings had been broken at point of
contact.
-----------------------------------------------------------------------------
-------------------------------------
					April 22, 1976
SB-104									Bulletin No:
Solid State Transceiver							SB-104-36

		                                Incorrect Wires In Harness

Wiring Harness [PN 134-887] should have a WH/BR/BR wire and a WH/BR wire
coming from BO#1 and BO#4.  In kits with series number 05551 harnesses were
found with two WH/BR/BR wires or two WH/BR wires at these breakouts causing
the unit to be wired incorrectly.  SB-104 store stock with this series
number should be checked for the correct wires in this harness.

Factory stock is being corrected.
-----------------------------------------------------------------------------
---------------------------------------
					April 22, 1976
SB-104/HW-104								Bulletin No: 
Solid State Transceiver							SB-104-37

		                             Low Sensitivity On All Bands

The following performance checks will help to isolate specific problem
areas in receivers with low sensitivity:

1.  Set the SB-104 fron panel controls as follows to prevent damage to the
signal generator if the transmitter is accidentally keyed:

		MIC/CW Level ------------------------- full CCW
		HI ----------------------------------------- out
		TUNE ------------------------------------ out

2.  Turn the receiver RF gain full CW.  With no signal applied, set the
volume control for a noise reference level that is high enough to mask the
receiver's own hum and noise.  If an IM-38 is being used to read the audio
output, set the meter to the 0.3 volt range, and then set the noise
reference level at -10 db. [Some of the following steps may require a
resetting of the reference level before measurement due to changes in
receiver noise level].

    NOTE:   In the follow two steps it will be necessary to isolate input
leads during
	signal injection.  This can be done by unsoldering input leads, or, by
	using the extender card with the pin 1 through 6 extender block shifted 
	over one space to isolate pin 1 on the circuit board.

3.  Isolate pin F1 on the F board and inject a 3395 kHz, .6 microvolt
signal through a .01 mfd capacitor to the pin.  The output should increase
by 10 db or more.  If not, the problem is probably in the IF strip or AGC.

4.  Isolate pin E1 and inject a 3395 kHz, .18 to .2 microvolt signal to the
pin.  Tune the signal generator across the filter passband; the output
should peak at least 10 db or better.  If not, the problem is the crystal
filter or its input and output circuits.

5.  Install the extender block properly on the extender card, and put the G
board on the extender card [pin 1 no longer has to be isolated].  With an
RF probe, check the voltage at pin G6.  This voltage should be
approximately .5 to .6 volts on 80M and 40M, and .4 volts on all other
bands.  If the voltages are significantly lower, the problem is with HFO
output amplifier Q405 or the appropriate HFO oscillator on the D board.

6.  With an RF probe, check the VFO voltage at pin G4.  This voltage can be
as low as .4 volts without seriously affecting receiver sensitivity, and
should be around .45 to .50 volts.  If the voltage exceeds .5 volts, reset
the VFO output level to .48 volts at the MIDDLE of the VFO range.

7.  Set the bandswitch to 80M and turn off the 80M HFO oscillator by
rotating the oscillator slug until the display shows 66XX.X.  Remove the
filter end of the jumper wire connecting C762 with the filter output bus,
and inject an 8.6 MHz, .8 microvolt signal to the jumper wire.  The output
should increase by 10 db or more.  If not, there is a problem in the 8.395
to 8.896 MHz bandpass filter.  If it is difficult to keep the bandpass
characteristic flat over its 500 kHz passband when tuning C764 and C769,
the Q of the [PN 40-1805] coils is probably too low, and they should be
changed.  Normally C764 will set the low end response and C769 will set the
high end, and the passband will be relatively flat.  The following
components make up the 8.395 MHz to 8.895 MHz bandpass filter:

	L725	C764	C774	C771
	L726	C766	R721	C767
	L727	C773	C769	C772
If the output of this step is acceptable, reconnect the jumper wire to the
filter output bus, and re-set the 80M HFO slug to start the oscillator. 
Tune through the oscillator range slowly, noting the output noise response
[adjust the VFO as necessary to avoid "birdies" and other spurious
responses].  A slight decrease in receive noise will be noticed at one
point as the slug is turned through the oscillator range.  Using this
minimum noise point as the final oscillator setting will give the best
signal-to-noise ratio on 80M.  The other bands can be tuned the same way,
but the effect will be less noticeable.

8.  Reset the noise reference level, and tune the receiver to 3750 kHz. 
Inject a 1 microvolt, 3750 kHz signal through a .01 mfd capacitor to pin
G24.  There should be a 10 to 12 db increase in output.  Check all other
bands at mid-band; the output should also be at least 10 db to 12 db
better.  If not, the problem is most likely in the Q of the bandpass filter
toroids, or, the bandpass filters have not been properly tuned.

9.  If the output in the preceeding step is accepable, insert the G board
into the chassis and watch for an INCREASE in the reference noise level. 
If this increase is 3 db or more, and the signal-to-noise ratio is equally
degraded, coil L729 is no longer self-shielding and must be replaced.

10.  If the output in the preceeding step is acceptable, connect the signal
generator to the receiver antenna jack and switch the antenna switch to
"SEP'.  The output may decrease as much as 2 db on 40M due to the
attenuation of the 8.65 MHz band reject filter.  If the attenuation is
greater than 2 db on 40M, or more than 1 db or all other bands, there is a
problem with the 8.65 MHz band reject filter. [See Bulletin No: SB-104-35].

11.  Connect the signal generator to the RF output antenna jack, switch the
antenna switch to "COM", and repeat step 7.  The difference in output
should be negligible.  Any additional attenuation of output indicates
problems with the filters on the ALC board, or with the antenna relay.
-----------------------------------------------------------------------------
--------------------------------------
					May 11, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-38

		                             Improved ALC Meter Action

The drive voltage developed at the base of Q302 is often insufficient to
swing the meter to full scale.  Change R322 from 10K to 6800 ohm [PN
1-27-12] to increase the drive voltage.  This change is being made in the
next production run.
-----------------------------------------------------------------------------
-------------------------------------
					May 11, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-39

			                           R11 Overheats

The 15 ohm current limiter R11 on lug 1 of the band switch is being change
from 15 ohm 1/2 watt to 15 ohm 1 watt [PN 1-12-1] to correct for an
overheating problem with the resistor.
-----------------------------------------------------------------------------
--------------------------------------

--------------------------------------
					May 19, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-40

		                                  SB-104 Modifications

The following list is a circuit board and chassis breakdown of
modifications that have been done to the SB-104 since introduction.

			CIRCUIT BOARD A

			- -NO CHANGES- -

		CIRCUIT BOARD B [PN 85-1580-3]

CHANGE				PART NO		REASON
-----------				------------		-----------
Change R-254 to 750 ohm		1-96		Increase 11 volts
Change C-227 to 47 mfd		25-223		Stabilize 11 volts
Change C-208 to .1 mfd		27-47		Reduce Leakage
Change C-222 to .1 mfd		27-47		Reduce Leakage
Change R-207 to 1.5 meg		1-36		Reduce mic gain

		CIRCUIT BOARD C [PN 85-1420-6]

CHANGE				PART NO 		REASON
-----------				------------		-------------
Add ground clip to 10 mtr coil cover	258-95		Eliminate 10M osc
Add 39 pF capacitor C-373 across R-314      21-167		Lower 40M spurious
Change C-332 to 50 pF		              20-97		Increase 15M
					      	              bandpass
Change R-329 to 12K ohm		1-14-12		Lower 40M spurious
Remove and discard C-322				Better keying
Remove and discard L-321 & C-348
Replace by attached procedure	              20-149		Reduce 3.395 spurious
				              40-1877		on 80 meter
				               31-76
Change R314 to 390 ohm		                 1-23-12	Reduce noise on XMT
Change R332 to 1210 ohm 1%		   2-68-11	Constant pwr output
Change C369 to 390 pF	 		20-106		Improve 80M
							 passband
Change R322 to 6800 ohm		1-27-12		Improve ALC/meter

		NEW 3.395 MHz TRAP ON C BOARD

A high level sput at 3395 kHz may be present in some units due to incorrect
tuning of the 3.395 MHz trap on the transmit IF board.  This problem can be
avoided by removing the old 3.395 trap on the transmit IF "C" board, and
installing a new trap as follows:

	1.  Remove and discard L321 and C348.

	2.  In the L321 circuit board holes near the top edge of the board install
	     an 8-40 pF [PN 31-76] with the slotted side toward the top end of the
	     board.

	3.  In the next lower set of holds, install a 150 pF [PN 20-149]
capacitor.
	     Do NOT use the holes screend for C348.

	4.  Next, install a 13.25 uH [PN 40-1877] coil at C348.	

	5.  Remove circuit board D, and pre-set the front panel controls to the
	     3.5 mHz band, MIC/CW level control full counterclockwise.

	6.  Put the meter in the POWER position, depress the HI and TUNE 
	     pushbuttons.

	7.  Turn the MIC/CW Level control full clockwise.  Adjust the 8-40 pF
	     trimmer for a minimum [null] on the power meter.

	8.  Turn off the unit, and reinstall circuit board "D".

		CIRCUIT BOARD D [PN 85-1418-2]

CHANGE			PART NO.		REASON
-----------			-------------		-------------
Change C-414 to 18 pF		21-60		Reliable 20M HFO starting

		CIRCUIT BOARD E [PN 85-1581-5]

CHANGE			PART NO.		REASON
-----------			--------------	-------------
Change R-625 to 22K ohm	1-45-12		Better BFO Switching
Change C-622 to 22 mfd		25-212		Better BFO Switching
Change 6-21 to 100 ohms		1-1-12		Reduce Transmit Gain
Remove and discard R-613			Improve 80M Sensitivity
Change R-619 to 100 ohm		1-1-12		Decrease background noise

		           VFO FILTER BOARD

CHANGE 			PART NO		REASON
-----------			------------		------------
Remove and discard R-1251			        Lower 10M spurs
		CIRCUIT BOARD F [PN 85-1462-4]

CHANGE			PART NO		REASON
-----------			------------		------------

Remove and discard R-569			Lower background noise
Change R-564 to 330K ohm	1-31		Better Muting
Change R-532 to .82 ohm		3-1-2		Stabilize audio output

		CIRCUIT BOARD G [PN 85-1708-2]

CHANGE			PART NO		REASON
-----------			------------		------------
Change C-703 to 105 pF		20-162		Better 80M sensitivity
Change C-707 to 105 pF		20-162		Better 80M sensitivity
Change C-764 to 8-40 pF		31-76		Better IF bandpass
Change C-769 to 8-40 pF		31-76		Better IF bandpass
Remove C-763 and discard
Change Q-701 to this------------	417-274		Increase sensitivity
Change Q-704 to this------------	417-274		Increase sensitivity
Change R-719 to 2.2 mfd choke     45-73		Increase sensitivity
Change L-734 to 4.5 mfd coil 	40-1875		Increase sensitivity
Remove L-733 and C787 and discard
Remove and discard C-742			Improve peaking
Change C-714 to 24pF		20-77		Improve peaking

		CIRCUIT BOARD H [PN 85-1422-2]

CHANGE			PART NO		REASON
-----------			------------		------------
Change R-954 to ferrite bead
     and wire			475-12		Reduce Harmonics
Change R-956 to ferrite bead
     and wire			475-12		Reduce Harmonics
Change L-952 to 4 turns				Reduce Harmonics
Change L-953 to 4 turns 				Reduce Harmonics

	      Refer to Pictorial 11-5 for PA Board

		          CIRCUIT BOARD J

CHANGE			PART NO		REASON
-----------			------------		------------
Change R-903 to 220 ohm 2 watt  1-13-2		Reduce Driver Temperature
Change RFC 902 with 390 ohms    1-48		Reduce Oscillations

		          CIRCUIT BOARD K

Remove and discard L814				Reduce Oscillations

		          DISPLAY BOARD

No Change

		          DC UP CONVERTER

No Change

		          VFO BUFFER BOARD

CHANGE			      PART NO	REASON
-----------			      ------------	-------------
Change R-1201 to 1200 ohms	      1-10		Eliminate FM
Change R-1202 to 350 mfd RFC         45-82		Eliminate FM
Change R-1203 to 470 ohms	       1-6		Eliminate FM
Change R-1206 to 150 ohms	       1-66	Eliminate FM
Change D-1201 to 1N458	                  56-24		Eliminate FM
Change ZD-1201 to 7.5V Zener          56-97		Eliminate FM

		          CHASSIS CHANGES

CHANGE			       PART NO	REASON
-----------			       -------------	-------------
Change R5 to 0.15 ohm	      	        3-14-2	Stabilize 5V regulation
Install 4 ferrite beads on wire 
   connected to K5		       475-12	Eliminate Oscillation
Install .001 mfd capacitor from
   F13 to F15		    	         21-14	Reduce "talkback"
Install a wire from F7 to asscess.
   socket lug 3		       			SB-644 Compatability
Install a 10 mfd from C7 to Ground
   [+side to C-7]		      	        25-54	Reduce T/R "pop"
Install 390 ohm from G5 to ground          1-48	Noise Blanker Compatability
Install 500 mfd from J1 to Ground         25-157	Improve B+ decoupling
Install .001 mfd capacitor from 
   pin 10 of relay to ground [C15]           21-140	Eliminate Oscillation
Remove and discard C4	       		              Increase power on 15 & 10 M
Install .1/100V from pin C4 to ground
Install a .01 ufd from pin C5 to ground
Install .1 mfd cap. from C4 to ground     21-195	Eliminate Oscillation
Install .01 mfd cap. from C5 to ground   21-176	Eliminate Oscillation
Remove wire between G2 and G3. Cut
   Orange 13.8 V wire running past G
   board.  Install both ends of this wire
   onto G2 and [S2].				Increase Sensitivity

		IMPROVING CW KEYING CHARACTERISTICS

1.  Remove two gray wires from lug 6 of R2.

2.  Connect this 6 1/2" gray wire from S4 lug 1 [R2] to the GND lug.

3.  Discard short gray wire going to R2 ground lug.

4.  Connect a gray wire from R2 lug 6 to terminal strip BE lug 3.

5.  Connect a 5 uF electrolytic [PN 25-149] between lug 3 and GND lug of
terminal strip BE; [+] lead to lug 3.
-----------------------------------------------------------------------------
-------------------------------------
					June 4, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-41

		                                Low Power On All Bands

Change:  R-332 from 1.2K to 1210 ohm 1% [PN 2-68-11].

This change will be in -02 level HW-104's and the -06 level SB-104's.
-----------------------------------------------------------------------------
--------------------------------------
					June 4, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-42

                                                     Improved Passband On
80 Meters

The 80 meter transmitter passband response is being improved by changing
C369 to 390pF [PN 20-106].  This change is being made in the next
production run, and should be made in all SB-104's received for service.
-----------------------------------------------------------------------------
----------------------------------------
					June 18, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-43

	                        ALC Meter Reads Above "3" On Transmit With No
                                                                   
Modulation

Variations in characteristics due to parts tolerances of ZD301 and Q302
will cause the ALC meter to read between zero and 3 when the transmitter is
keyed without modulation,  Change ZD301 and/or Q302 until a combination is
found that brings the meter reading below 3 on the scale.
-----------------------------------------------------------------------------
----------------------------------------
					June 18, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-44

		                                 Stabilizing 80/40 Meters

The 80/40 output should be stabilized in all units received for service by
making the following change:

	Change R345 from 1000 ohms to 100 ohms [PN 1-1-12]
	Change R343 from 1000 ohms to 100 ohms [PN 1-1-12]
-----------------------------------------------------------------------------
----------------------------------------
					June 18, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-45

		                    Improving The 40M Transmit Passband

The 40 meter transmit passband can be significantly improved by making the
following change in all units received for service:

	Change C-342 from 75pF to 62PF [PN 20-109].
-----------------------------------------------------------------------------
----------------------------------------
					June 18, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-46

		     	                Eliminating Transmit Chirp

Chirp may be experienced during CW keying; the following change should be
made in all SB-104's received for service:

	Change C6 from 500 ufd to 1000 ufd [PN 25-219].
-----------------------------------------------------------------------------
--------------------------------------
					June 18, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-47

			                         VFO Filter Board

A change in screening is being made on the VFO filter board, changing the
board from PN 85-1516-1 to PN 85-1516-2.  Components will be deleted from
the new board and the remaining components are being re-numbered, as
follows:

	85-1516-1 [Old Board]	85-1516-2 [New Board]	Value
	-------------------------------	--------------------------------	--------
FROM:	R-1255		       TO:R-1252			150 ohms
	R-1254			R-1251			  68 ohms
	R-1266			R-1253			  68 ohms
	C-1254			C-1252			105 pf
	C-1256			C-1254			105 pf
	C-1253			C-1251			 .01 uf
	C-1255			C-1253			620 pf

The new board will be incorporated in all future productions runs.
-----------------------------------------------------------------------------
---------------------------------------
					June 22, 1976
SB/HW-104								Bulletin No: 
Solid State Transceiver							SB-104-48

	                               Change Capacitors To Higher Voltage Caps

Make the follow changes in all SB-104/HW-104's received for service:

Change:	C-321 from PN 21-95	TO	.1 ufd mylar [PN 27-47]
	C-309 from PN 21-95	TO	.1 ufd mylar [PN 27-47]
	C-906 from PN 21-95	TO	.1 ufd mylar [PN 21-47]
This changes the capacitors to ones with higher breakdown voltage ratings,
and increases the RF bypassing.

((((NOTE:  PN for the .1 ufd mylar replacement of C-906 is as shown on
fiche))))
-----------------------------------------------------------------------------
-----------------------------------
					June 22, 1976
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-49

		                             Erratic Display On 10 Meters
 
Erratic display on 10 meters can be caused by R-1252 loading the VFO line. 
Clip and remove R-1252 [470 ohms] on all SB-104/HW-104's received for
service with the PN 85-1516-1 board installed.
-----------------------------------------------------------------------------
--------------------------------------
					August 3, 1976
SB/HW-104								Bulletin No:	
Solid State Transceiver							SB-104-50

		                                      Better Carrier Null

A null should be obtainable at two different settings of capacitor C-648;
either setting can be used.  If there is only one setting that gives a
null, remove C-645 [33 pF] and repeat the null setting adjustment.  If
there is still only one setting that gives a null, install a 62 pF mica [PN
70-109] capacitor at C-645 and repeat the above step.
-----------------------------------------------------------------------------
----------------------------------------------------
					January 12, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-51

			              Low Output Power on 15 Meters

++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					February 4, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-52

			                                 VFO Drift

++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					February 4, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-53

	              Driver Transistor [PN 417-820] Installation at Q901 and Q902
                        

++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					March 17, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-54

	      	                                        Circuit Changes
                         
++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					May 27, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-55

	                                         Low Gain in HFO Amplifiers       
                 

++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					October 10, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-56

	            Audio Level Control of Receiver Does Not Completely Reduce
Volume
                                              
++++Information not available at this time++++
-----------------------------------------------------------------------------
-----------------------------------------------------
					November 10, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-57

	                                               Drivers Overheats in
Standby
                                              
++++Information not available at this time++++
-----------------------------------------------------------------------------
----------------------------------------------------- 					November 10, 1977
SB/HW-104								Bulletin No:
Solid State Transceiver							SB-104-58

	                                                  20-Meter Power Roll-Off
                                              
++++Information not available at this time++++
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					February 2, 1978
SB/HW-104(A)								Bulletin No:
Solid State Transmitter							SB-104-59

			                                VFO Dead

Check the solder pads at each corner of the PN 85-1205-3 circuit board to
confirm that all solder resist has been scraped away.  If the solder resist
is not removed at these points, the oscillator will not run since the board
is not grounded.
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					March 31, 1978
SB/HW-104(A)								Bulletin No:
Solid State Transmitter							SB-104-60

	                                 PA Board Cracks Or Transistors Break

When installing the four 360 pF capacitors in the SB-104 "mod kits" on the
foil side of the PA circuit board, mount them as close as possible to the
circuit board to prevent breaking the board or the power transistors when
the heat sink is installed.

These capacitors were added so the PA would be more stable if used with an
antenna tuner on 10 M.  Production SB-104A's will have these capacitors
mounted on the component side of the PA board.

Since the vendor is unable to supply us with 360 pF capacitors which are
thin enough to be mounted between the circuit board and heat sink, the PN
830-24 "mod" kits are being inserted to instruct the customer not to
install these capacitors.
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