The small amount of RF apparently being produced by your pile of fakes is probably leaking through from the driver transistor prior to the final rather than the result of any amplification being done by the fake its self.
Probably although the other fakes from the same batch don't have any leakage ? but that said you don't actually know what they originally were before the Chinese put their fake part numbers on them.
ive got same problem with audio transistors. c2705s that have huge amount of harmonics going on and far too much gain. Its even worse with output transistors like toshiba 1943s etc. Ive no idea whats in the resin but sure as hell not whats on the silkscreen. ive just about used up my original stock i bought in the 90s and im yet to receive any genuine parts from china. im not sure what the answer is, most parts are obsolete now so pretty stuck really.
I have used sellers like Polida and had a lot of genuine stuff, although they are pricey stuff like audio ic's which are pretty hard to get, i will avoid little-diode all day long, they sell 99% fakes... i have yet to buy anything that's genuine. Nikko in the past has sold genuine, but this recent batch of C2509 were obvious fakes.. i tend to use Aliexpress now days though, you get the same protection as ebay and you just look at the sellers, if they picture a genuine item, you must assume that's what they'll sell, if it's fake, instant return and refund because it's not what's pictured..but that said i have had a few good items from Aliexpress.. it's a gamble, but as long as you have protection you can take the gamble.
Unlike fat fingers or the other radio narcissist's that are on youtube i don't do this to make money and a living from it. so i use a basic mobile phone and crap lighting.. if you feel liker you want to subscribe and pay some money feel free.. :)
not really, but a simple way is if you have a good radio to use as a receiver, either HF set or a CB that's on frequency with a needle meter, with the RF gain down or so the needle is half way on the meter give it some audio talking as you would normally, the the needle starts to go backwards it's over deviating, so adjust the deviation until the needle stops moving with your voice and is stable.. i found using a President lincoln that once the needle (LED) stops flickering the deviation is around 3khz, which is a tad high to the manufacturers spec, but i set all mine at 3khz as normal voice will be around 2.5khz most of the time..
Yes i agree, that's why you use a 1khz tone and either a good ear,or a scope to show it is receiving correctly then using the same tone and multimeter peak up the RX.
try my Uniden bleed box test and see.. in all fairness Cybernets receive more as they have better amplifiers in the RX stage, Uniden have better filters so less noisy. but it's down to owners preference, so claim Unidens are great, others Cybernet. yet Maxon are as good also but get forgotten.
Where do you connect the red and black probes of the signal meter? And what did you have in the mic jack? What’s its purpose? I wanna learn to do it this way.
red and black probe go to the two wires on the signal meter, or black to negative power lead and red to positive of the signal meter. the item in the mic socket is a receive audio short, this radio requires a link from ground to RX audio to get sound from a speaker, so the plug in the socket is just a link to enable sound.
Ok thank you so very much. I have a Koolertron DDS 60MHz Signal generator I use to send a 1KHz tone three the mic jack to see the waveforms on my scope. I’ve always wondered how to use it to check the receive and was contemplating buying a SINAD meter but your video brings up a valid point about the needle in the meter bouncing around making it difficult to get an accurate reading. Still new to the CB repair game and always willing to learn more. I’m assuming this method will work any radio so I’m still learning. If it’s not to much to ask could you explain the whole voltage thing to get a S9 signal. Not sure if your familiar with the Koolertron DD Signal Generator or not, but from what I was gathering from this video was I take my BNC to PL259 coax from output channel 1 and connect it to coax connector on the back of the radio, set the signal generator to 27.185 MHz (Channel 19) or 27.205 MHz (Channel 20) or water ver channel I’m gonna use to check the receiver, then set the tone to 455 MHz and use a multimeter connected to the power & ground probes on the signal meter of the radio. What does the multimeter have to be set at? Is 455 MHz what the tone needs to be set at? A cheat sheet would be amazing to have of this procedure. Sorry for this long replay and questions.
@@765-AMPS ok, you can use a scope and tone and RF signal generator as a form of Sinad also.. as you say you view the waveform on the scope....connect the scope to the speaker.. you can then inject the RF signal to the antenna which also has a 1khz tone and vie won a scope, weaken the signal and the wave form goes distorted and dirty, as you peak the RX on a radio the wave form become cleaner and solid, so here you are cleaning up the received signal as heard in the speaker, so in effect bringing up the receive signal making it cleaner is working a similar way to using a sinad meter, the sinad works the same way, so you can use a scope as a form of sinad meter to obtain the same results, you just don't have the signal levels as in -115dBm to 12dB sinad, but if you're only interested in peaking the weaker stage of a radio for better reception the scope works good, then as long as your generator can send out a -73dBm signal this is to set the signal meter to be an S9 reading.. on the 455khz signal some radios will use this type of signal as a way to get the RX on frequency as not all TX and RX frequencies are the same. but experiment in different ways and find what gives you the best results., but ideally locate a radio service manual and read the procedure they suggest and see if you can obtain similar, same or better results trying different ways to peak the RX.
@@765-AMPS usually around 2v the readings will be less than 1v depending on the radio.. sometimes at full signal you may get over 1v on some radios, others barely 500mV you have to find yourself what works best for you., i find inject a strong signal, S9 perhaps, put the multimeter on and check reading, then lower the signal, when i see the voltage move up and down a large amount then i use that setting, also to note some radios the reading will actually decrease as the signal gets stronger..!!
Been there and i have a few but i just get a mic made up and never tried fixing a new coffin ⚰️ mic all my radios with that type of mic have been converted to coffin ⚰️ mic and i am happy
Got all my radios sorted by a very good rig ham doctor and the base Fidelity and a few more base a murphy home base that was a very whine radio and radios that were like that got fixed the Dnt base and Dnt mobile i have two Dnt base radios and two Dnt mobiles and a super tuned great radios when you get them working righ 4w out and a very nice a valve bremmi kick loved it and a thunderpole mk3 and a good silver rod good for local dx.and the thunderpole for some great contacts dx contacts and great ground wave contacts were i lived to Saint andrews not bad
I enjoyed the video. All I can say is that there is the right way and there is the wrong way, there is the trained way and there is the amateur way. I'm not saying which is best. Tis up to the end user to decide that.
you are right there's the 'right way' but as proven by many people the 'wrong way' can equal or be better than the claimed 'right way' each to their own, i have two Sinad capable meters, and i won't use SInad.
Great video. Just a question , where do you connect the multimeter 's red claw to the radio to extract this measurement ?? The point was not very clear.
very sorry. i connect to positive connection on signal meter. this i usually set my meter on 2v setting and will see readings from 0.30v up to 1.50v depending how much signal is received (and meter setting) you cna also connect on to 'wiper' of the signal meter VR..
Sorry, I disagree, a sinad meter was created for a reason, and your statement " that's just the discriminator" is rediculus, tuning the rf stages for maximum signal is all well and good, but tuning the discriminator for maximum signal to noise ratio in an fm set is more important. , you can have an s9 signal and zero audio if the discriminator is out of tune. . So many "experts" on here , full service.? Don't forget the air filter ,lol
No offence but you're talking tosh.. the discriminator or detector as another yourtube rig doctor calls it is done usually before you drop the signal and peak RX and double checked afterwards., this can be done on a scope to see the maximum peak in audio, using your ear for maximum deafness :) or even a volt meter across the speak for maximum voltage. my point is, you don't need a Sinad meter to peak RX, this is proven FACT by watching the other white coat wearing rig tech video's as some of those radios are actually mine and he admits "he can't get them any better" Also using a volt meter on the signal meter is more stable than the method shown using Sinad.. i mean after probably 30 years of doing it this way and hundreds of radios sold via ebay i've not had one bad comment of a radio being deaf, quite to opposite.. send me a radio or try it yourself..
I had two and i had no problems we lived on a street and in between to cb lads and the run 500w and all ways heard them up and the freqs but it proves nothing
It was.. when Nottingham CBers started to take over channel 6 and spoil it for everyone else who was listening. same as they did 446, and do now on channel 19.. :)
Just search ebay for 'ceramic screwdrivers' but be aware being ceramic they can break easily if you are heavy handed, same with the cores, if you use the wrong size or they are stiff they can crack cores same as a metal driver can.
This method is not perfect, but does work to a degree, The reason if you use a signal gen and say you can hear the tone at 1hz -127 dbm with a DVM you can test at signal meter to get a MV reading as shown. but the first coil in the receiver you can open to give a higher reading on the DVM yet obliterate the Signal gen tone you can hear. as you Adjust to get higher DVM reading you are really letting in more noise to the receiver, this higher noise level gives you a higher DVM reading, this in turn makes weak signals disappear in the noise. A sinad meter shows you this. After setting first receive coil with a sinad meter, you can then use this method best with a DVM with micro volt reading and set receiver to highest reading. The same as you can set the FM detector using AC on a DVM for highest reading using speaker wires to AC DVM instead of scope as it will read siniwave in AC mode. Interesting video though and as stated in some tune up vid's wild adjustments on coils are no wear near good enough for a sweet receiver. best to go through it several times. cybernet FM rigs always had that awful pop in Squelch when the setting was just above noise floor with a kind of growl and pop as it opened to weak signals. To cure this and have a sweet squelch solder a 25v 16uf to Q14 on the emitter - and + to collector. pop and growl now gone and sweet squelch. Great to see people tuning radio's 👍
I appreciate the reply, but practise quite often proves my way is better. i have been doing it this way for years and the amount of people who say they can now hear weaker signals better is amazing, and also a few of my radios have ended up going to Richard at Grantham and he himself can't not get them any better, proven in his video's (even an email he said he doesn't know why people send them as he can't get them better) there's the proper correct way, which works and is what used in the factory, and there's mine and other peoples way which works just as good if not better, and remember the factory alignment it a quick twiddle and within 5% or 10% mine is after 20 minutes warm up and checked several times before i'm happy with the outcome.
I was actually expecting a hammer to come out to compress that mic insert.😂I have one of those NATOs in the spares box from absolutely years ago.I will try and dig it out.
They can be a bugger, but they fit well enough, just remove all the part shown and ideally a bit more off the holder clip and screw and they fit perfect, as it's tight no wobble or insert moving noise.. they sound decent too being 600ohm they're ideal for CB.
I've tried two Sinad meters and i get meter results using my old Altai needle meter, i use the digital to show how to do it easier, i use this as often also. i did a Uniden 100 yesterday and they show negative voltage off the VR but the numbers just need to increase, some radios the numbers need to go down, but you figure it out as you increase and decrease the input signal. so much easier and more accurate than a Sinad meter.
cheers, it's not intended to be too technical and using big words that go over some peoples heads, i try to make it easy so it helps everyone out. hope it helps a few people in the future.
Midland dnt mobile and base early Midlands Baracuda sapphire to name lots more it's time to have a look in my mic drawer and the all named so I knew were they go
Hey. wires don't solder like that! remove the microphone plugs from the radio, because the electromagnetic field from the soldering iron will damage the input track.
40 years never damaged a radio yet :) although the grounding of the Iron can make the radio TX or produce RX but 'electromagnet field' erm.......... that's a video you can do for us to show how this happens maybe :)
There not that bad you can get it sorted and they were better as I said before we lived in a street both ends had cb and 500w kickers and I heard them up and every channel on all my radios had a word and the dropped it down 25w and it was lots better and no bleed over but there is not a lot on these day so bleed is nothing 39 channels to pick from my self I run Am ssb FM midband and very little uk40.
I used to change the ceramic 10.7 filter for a dual pole crystal filter then they were a lot better. Even the FM detector IC output sounded normal then with no signal present. A Fidelity 3000 base had this board in.
This video was on my other channel for a few months, but seems no one really saw it, put it on here and it's had as many views in a couple of days. Any how can't stop, off to dye my Mohawk.
no this one was after that, that 706 i sold a year or so later, but missed it so much i bought this bag of shit show in the video. funny thing was this one in the video had the serial id sticker missing also.. hmmmm...
