This house has a Honeywell Accenta G3 alarm system. If the main unit loses power for any reason, the external siren sounds - even if the alarm is not even armed! Entering the code to disarm it is not an option as the keypads are completely dead when the power is out.
I presume this means the backup battery inside the box has failed, but I can't get in there and replace it without also setting off a tamper alarm! Is there any way to disable the tamper alarm so that electrical work can be carried out with the power off? Or a way to replace the backup battery without setting off the...
Tom41
Badcaps Veteran
Last Activity: 08-31-2023, 04:00 AM
Joined: 10-27-2005
Location: Leeds
-
Re: Panasonic VCR horizontal line
Being in a PAL region, EP mode was never really an option with our VCRs. I tried to avoid LP mode as much as possible due to the quality degradation, and the vast majority of tapes I've tried have been in the SP mode. Regarding the original VCR that recorded the tapes, that was from 1988 and was thrown out many years ago. I have also seen the noise line on store-bought movie cassettes though, and they certainly wouldn't have been recorded by a defective machine!
The problem is extremely minor at the moment, and the VCR is certainly...Last edited by Tom41; 01-28-2019, 11:31 AM. -
Panasonic VCR horizontal line
I recently obtained a Panasonic NV-HD100 VCR that I was hoping to use to transfer VHS tapes to computer. While the mechanics of the loading and handling mechanism seem perfectly fine, there are a couple of small issues with the picture.
Firstly, there is a very fine noise pattern all over the image. It's possible however that it would have looked better on an old CRT TV and the modern HDTVs are just showing it up better. If I turn the sharpness control right down, the pattern is suppressed but of course then the image is very soft; not what I want.
The second, and... -
Sanyo VHR H793 won't accept tape
I have recently obtained a Sanyo VHS player that I was hoping to use to back up old VHS recordings to DVD and computer. Mechanically the machine looks completely sound, and all the electronics are working... except I can't play a tape! When I try to put a tape in, I get no response from the motors at all. Applying further pressure to the tape results in the spring spitting the tape back out when I release it; with no attempt to load it in.
On rare occasions if I jiggle the tape around with the lid open, it'll sometimes trigger the loading sequence. At this point all functions (play,... -
Masthead amplifier power issue
We have a masthead amplifier on our outdoor TV antenna to improve reception, with a power unit indoors that sends +12v DC up the antenna cable to power it. But whenever a TV is connected to the antenna cable in the living room, all other TVs in the house go off and the PSU shows a red light instead of green. I just checked with a multimeter, and the masthead is sending the +12v straight back down into the living room instead of the signal! The other TV points in the house show no voltage on the antenna cable.
The amplifier is designed to accept power from any of the TV points in... -
Re: Two SONY VCRs eating tapes
Unfortunately the vcr shown in this video is quite different to the ones I have, at least what I can see through the tape slot. For example the pinch roller didn't move up and down when loading, and nothing looks out of place...Leave a comment:
-
Two SONY VCRs eating tapes
I have recently obtained a pair of SONY VCRs; different model numbers but I'm 99% sure they have the same insides. I was hoping to use them to transfer some old tapes to digital files, but both of them failed in the exact same way a short time after I started using them. First they were making a slight knocking noise. Then, during a rewind operation the VCR suddenly stopped and ejected the tape still unspooled from the cassette. They now unspool and eject every single cassette that is put in, making a whirring sound that's MUCH louder than it should be.
Clearly there's something... -
Is this PSU capacitor bad?
My PC was failing to stay powered on and seemed to have to 'warm up' before it could be adequately used. Frequently it would just power itself off again mid-way through the POST.
Opened up the computer, nothing obviously wrong with the motherboard or connections. Then I popped the lid on the PSU and saw... THIS.
My question is, is this capacitor leaking gunk, or is it just something they put on in the factory to minimise vibrations (as I've seen on other PSUs)? You'd think that if it was the latter, there would be similar stuff on the other input capacitor...
Certainly... -
Technics KN550 muting
I have recently discovered my old Technics KN550 synth that I used to play on back in the 1990s. I powered it up and it still works, with one minor issue - the speakers don't make any sound! I can hear the output through the headphone jack, and while inserting and removing the headphones sometimes one of the speakers will crackle and turn on momentarily.
I suspect this is an issue with the cutoff circuit that mutes the speakers when you plug in headphones; it's activating even when there are no headphones plugged in! Hopefully this would be an easy fix - any advice? -
Mixed mode CDs on audio players
This is a mini-rant about how Mixed Mode CDs no longer play properly on modern audio equipment, due to the MP3-CD compatibility many of them have. I have many CDs that were made in mixed-mode format, mainly from video games in the 1990s and I used to like listening to the audio tracks on my CD player.
The problem is, when a modern CD player sees the data track, it assumes the disc is an MP3 CD and starts looking through to find MP3s to play. My main hi-fi is like this - searches the data track for a few seconds, and then stops dead with a 'no file' message. It completely ignores... -
Audio tapes and magnets
Not sure whether I should post it here or in the general electronics, but it is related to audio equipment!
As you know, signals on audio tapes will print through to adjacent layers if the tape is left wound up for a long period of time. In the past I have had the misfortune of leaving a tape near a weak magnet, and hearing print-through and partial erasure on just the part of the reel that was exposed to the magnet. I have therefore experimented using an old tape with recordings I don't care about.
My first experiment was to recreate the print-through effect I heard... -
Mystery audio device (educational)
Just wondering if any of you could help me identify an old audio player that I used in school back in the 1980s. I do not remember the make or model of it. All I remember is that the medium was a sheet of A4 paper that had a magnetic backing. After inserting the paper, lining the holes up with the pins to make sure it's in the right place, the lid was closed and a playback head started revolving underneath the paper. The head gradually moved in from the edge, tracing a spiral track.
So it was like a record player, but using magnetic recording technology where the head moved instead... -
Re: Frequency sweep on audio tape
I'd say the theory of the tape being saturated/clipping seems right. I recorded over the sweep with some speech, and could still faintly hear the sweeping tone upon playback - almost as if the tape was too far saturated to be fully erased.
I also recorded the same sweep (from the same CD) twice; once on a cheap boombox and again on the expensive hi-fi. Looking at the spectrograms, the pattern of tones going up and down was quite different on the two recordings! Must be some sort of resonant frequency - perhaps these could be used to...Leave a comment:
-
Re: Frequency sweep on audio tape
I thought 'clipping' was only to do with the strength (amplitude) of a signal, not its frequency.
I generated the sound with Audacity, burned it to an CD as full uncompressed CD-DA audio, then put the CD in an expensive hi-fi system. I played the CD there and used the hi-fi to record to cassette.
To rule out any distortion caused by the CD decoding, I also recorded the CD output from the hi-fi and the trace looked almost exactly like the signal I generated in the first place. Only when playing back the cassette did these extra...Leave a comment:
-
Frequency sweep on audio tape
Recently I recorded a frequency sweep (low to high) on an analogue audio tape, trying to see what is the highest frequency it could properly reproduce. To my surprise, when I played it back I heard other tones going all over the place - downward sweeps as well as upward!
I've attached a picture of the spectrogram. The top shows what I recorded to the tape (generated in Audacity), and the bottom is what I got on playback.
Anyone know why this might have happened? Something to do with harmonics or 'reflecting' signals? I wonder if tapes inherently have some sort of... -
Buzzing guitar amp
Not too long ago, we found my sister's old guitar amp. Upon powering it up, it soon became clear there was something wrong with it. A full-volume 50hz buzzing was coming out of the speaker at all times, and turning the volume control did not have any effect on the sound. I could very faintly hear the input signal coming out of the speaker as well as the buzzing, and that WAS affected by the volume control - however it was hard to stay near the amp when it was making that loud buzzing!
We've thrown out the amp now (so I can't get the make and model), but I wondered if any of you... -
Re: Cassette player dropouts
Ok, some further information. I managed to make a recording of the dropouts happening (can't post it here, as it won't let me attach an MP3). You can probably see the two gaps caused by the cassette player, and I assure you there is no gap in the music at that point on the tape. Looks to me like an amp problem - the sound abruptly cuts off, remains silent then quickly fades back in. Could it be the caps? Doesn't seem to be affected by moving the unit around or tapping it...
Also there are no mechanical switches to get dirty on this. All...Last edited by Tom41; 09-12-2014, 01:47 PM.Leave a comment:
-
Cassette player dropouts
I have an old SONY 'boom box' style cassette/cd/radio unit that's developed an annoying issue. When playing tapes, the audio randomly silences for a short time then comes back. There doesn't seem to be any pattern in the silence frequency or duration - I've had silences that last a split second, and others that last several seconds!
The problem is definitely with the cassette player, not the cassette. When it silences, if I wind back the cassette and listen to the same point again, I hear the audio as it should be. Also the CD and Radio don't seem to be affected by this issue.... -
Moving coil meter with audio signal
One time when I was young I had an old-style moving coil meter, that I think was set up to measure voltages. I decided to try putting an audio signal from a cassette player into it. I was expecting the needle to bounce around like the level meters on audio equipment, but something quite unexpected happened. The needle barely moved up the scale, but started to vibrate reproducing the audio like a miniature loudspeaker! Putting my ear on the meter I could clearly hear the audio from the cassette.
Any idea why this happened? Perhaps I would have been better with an AC voltmeter? -
Thermal plug fuse?
We recently had a defective cable TV box replaced. The engineer also replaced the power cord, stating that our old plug contained a 'thermal fuse' which they don't use any more. I thought there was only one kind of BS1362 plug fuse; a small piece of wire inside a cartridge... can anyone elaborate on this? What kind of fuses are used in British mains plugs?
No activity results to display
Leave a comment: