patulong po sa tone control

[badalicious]

Another classic symptom of parasitic oscillation. This is usually layout related. We can help you further if you show your layout.

A quick fix that may work is to reduce the bandwidth of your transistor amps. This can be done by increasing the value of capacitor C2 and C12. You can try using 100pF-470pF.

Be reminded that you should use linear type potentiometer for VR1,VR2 and VR4. Linear type pots are denoted with 'B' suffix (e.g. 100KB, 5KB) VR3 should be audio tapered ( identified with 'A' suffix e.g. 100KA, 50KA).

Finally, using a single pot for VR4 is a bad idea. You can't get a stereo separation better than 30dB with a single pot because it will allow excessive crosstalk to bleed through each channel. Use a dual pot instead.

pinaliptan ko po ung c2 & c12 ng 470 pF.ganun parin. Pero this time pagtinouch ko ng finger ung R2, may nasasgap siya ng radio signal diko aure kung Am or FM.basat may nagsaslita na radio station.

[pEN DoTA]

parang nakita ko na ito sa libro ah

nde ba ito yung kay pagirigan
yung pulang book?? 

tama master danny, pagarigan ang author.
ung kay pagarigan ang usually ginagamit sa mga karaoke box we back in 1980's yata, maganda ung tunog ng mga un.
cguro sa pcb layout ung problema ng t.s. mas mabuti cguro e reivew nya ung lay out nya, baka may mali. if wala namang problemang im sure tutunog un.

[badalicious]

Another classic symptom of parasitic oscillation. This is usually layout related. We can help you further if you show your layout.

A quick fix that may work is to reduce the bandwidth of your transistor amps. This can be done by increasing the value of capacitor C2 and C12. You can try using 100pF-470pF.

Be reminded that you should use linear type potentiometer for VR1,VR2 and VR4. Linear type pots are denoted with 'B' suffix (e.g. 100KB, 5KB) VR3 should be audio tapered ( identified with 'A' suffix e.g. 100KA, 50KA).

Finally, using a single pot for VR4 is a bad idea. You can't get a stereo separation better than 30dB with a single pot because it will allow excessive crosstalk to bleed through each channel. Use a dual pot instead.

pinalitan ko na po ng 470 pf.ganun parin.

tapos bakit pgtinatouch ko ung terminals na malapit sa t1 may nasasagap sa radio signal di ko sure kung am or fm?

any idea?

[freshgrad]

mga master san po kya ako makakabili ng murang knockout puncher kailangan ko po ng sizes n 1/2" inch to 2" inches......tnx po in advance

[pEN DoTA]

mga master san po kya ako makakabili ng murang knockout puncher kailangan ko po ng sizes n 1/2" inch to 2" inches......tnx po in advance

hijacker
post mo sa new thread

[Woots29]

ok heto na tayu sa trouble shooting..

may bias voltage ba sa input ng transistor tr1?

check thru voltmeter base and emitter of tr1 kung may 0.5 volts

[pEN DoTA]

parang sa input side ung problema mo t.s. review ur layout baka nag kashort ung input to ground.

[rgv101]

tapos bakit pgtinatouch ko ung terminals na malapit sa t1 may nasasagap sa radio signal di ko sure kung am or fm?

any idea?

AM yan sir...

baka mismatch ang tone control sa amplifier kaya ganyan...

[badalicious]

itry ko muna ilipat sa maaus na pcb

[Woots29]

^ayan cge update mo kami.

[pEN DoTA]

itry ko muna ilipat sa maaus na pcb

good idea.

[Woots29]

wat balita dito?

[ultrasonic™]

pinalitan ko na po ng 470 pf.ganun parin.

tapos bakit pgtinatouch ko ung terminals na malapit sa t1 may nasasagap sa radio signal di ko sure kung am or fm?

any idea?

AM radio station channel  yan...
cause  yan  ng body interference natin... our human body are considered as a good catcher of RF signal  kaya may tunog o nabubuong radio station

@TS sang-ayon  aku sa mga comments  ng mga  masters  liitan  mu  muna ang mga pcb loops mu..  gandahan mu ang soldering.. baka may  cold solder pa kayo..  gamit  kau  ng  mga shielded  wire para  avoid more audio distortion

[Woots29]

nu kaya update dito?

 

[badalicious]

cnxa n mejo ntagalan updatesklo.ngaun lang kc ulit nagkatym gumawa. nalipat ko n sa maaus n pcb. ok naman ang tunog kaso problem ko humming, parang grounded. pero ok naman ang sounds.

no po kaya pwed gawin.tnx

[pEN DoTA]

proper ground ang kulang. use shielded wire sis.

[badalicious]

shielded wire naman gamit ko except ung connection from VRs ng bass and trebble control.dati kc ung gamit ko dun ung sheilded na pang stereo, gunun din, naghuhum din.ngaun pinalitan ko ng stranded na maliit n wire.medyo humina ung hum pero audible parin.

[Rogelio]

Sir, parang ung diagram mo, galing sa book,, na ung grren na book ni RSP... electrolab din  ung included eh practical rewinding.... check or verify mo ung connection, sa pcb board kc minsan my mga discripancy... sa pcb lay out....saka ung mga suply mo paki check.

[badalicious]

^^ung pcb layout ko po galing dun sa kasama ng circuit,provided na siya.xnerox ko n lang.ok nman ung etching wala namna putolputol. ung supply, galing n din sa supply ng main amp ko. trinay ko n rin idikit dirct sa pcb ung VRs para wala nang mga wires. ganun parin may hum pa rin

tapos another problem pa po pala.kc tinrsting ko siya sa malaking speaker, parang walang bass sound.pag inadjust ko kc ung bass control hindi nagbabago ung tunog.pero ok ung trebble naadjust.

[Woots29]

so galing sa power suply ang hum nyan. malamang grounding problem mo

may case ba yan?