Re: WTF is this? Tru Tone Model 300A
try searching for the valve numbers 35Z5 -12SJ7 50L6 and see if it matches any schematics .
try searching for the valve numbers 35Z5 -12SJ7 50L6 and see if it matches any schematics .
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Re: WTF is this? Tru Tone Model 300A
Looking at the guts, I think this must be some sort of transmitter. Its ΒΌ" jack feeds to a pot that's capacitively coupled to the grid of the 12SJ7 grid.
Likewise the 50L6 plate seems to be coupled to coil and the pigtail "antenna" output. It's too simple to be anything other than AM as far as I can tell. Drat, still looking for a cheap SSB transmitter.
Next is to somehow figure out the frequency... if only I had a spectrum analyzer, that'd make it real easy...Comment
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PCB ID - Core model
v218470 - AMD/215-0767003
v218510 - AMD/215-0767003
v27314s HD7850
v27937s - HD7730
v310440 - GM107-400-A2
v313070 - GK208-201-B1
v313080 - GK208-201-B1
v313120 - GK208-201-B1
v313130 - GK208-201-B1
v313140 - GK208-201-B1
v313220 - GK208-201-B1
v31609s - GM204-200-A1
v31615s GM204-200-A1
v316320 - GM204-200-A1
v317290 - GM204-200-A1
v32002s - GM206-300-A1
v320040 - GM206-300-A1
v32005s - GM206-300-A1
v32010s - GM206-300-A1
v320115s - GM206-251-A1
v320120s...10-02-2024, 09:21 AM -
I really hope someone will be able to help me?
I have recently moved house and dismantled a working 5.1 home cinema
system. Unfortunately when putting it back together again I get no
sound out of the sub, I'll try and give you as much (probably too much)
information to hopefully allow you to sort my problem, or at least
point me in the right direction.
* My system consists of a Yamaha DSP-AX861SE AV receiver connected to
various sources and outputting through speaker cables to 4 x Monitor
Audio Radius 90s, 1 Radius 225... -
My garage alarm siren was sounding a bit quiet and the tone was weird, like mixed with another tone.
Powered up it draws about 14V 300mA with a spike to ~1A briefly during the low pitch yelp, seems normal.
Teardown reveals only two electrolytic capacitors inside, so I replaced them. 100uF 25V for the warble ramp, and 47uF 16V for decoupling.
The old ones tested OK sort of? - 100uF reads 68uF (-32%) ESR 0.80Ω, and 47uF reads 41uF ESR 0.87Ω as well so it was a bit confusing if the caps were to blame.
The tone caps are green film caps I left alone. Newer... -
For this Dick Smith TV GE6878 (Thompson) I replaced the broken remote with a universal it kinda works though if its more than a few meters away sometimes the buttons register and sometimes they wont so I bought another remote from another brand and it has the same problem, I've had an old TV in the past that the sensor died completely and I replaced it to fix it could this be a similar problem? I tried looking for a service manual, spare parts for a receiver and a parts list but I couldnt find any info. can someone please help me to find the info online for a service manual or where I can buy... -
Everyone -- I am trying to troubleshoot my NAD C740 stereo receiver, which either won't power on or won't consistently stay powered on.
I will start by saying that I am a hobbyist, and while I am decently handy with basic DC stuff, I am more hesitant when it comes to mains-powered equipment (that is, reluctant to poke around with a multimeter when it is powered on)
The central issue is that after a long period of non-use, the receiver powers on and all functions seem to behave normally, but after a couple of minutes, it powers itself off.
If I attempt...
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