Transistor Radio Repair: Hacker Hunter Swept I.f. Alignment
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- เผยแพร่เมื่อ 8 ก.พ. 2022
- In this video I do a swept I.F. alignment on a Hacker Hunter transistor radio. This method is superior to just peaking for maximum signal strength because it allows for the full bandwidth of the signal to give the maximum sound quality. Using xy mode on my digital oscilloscope with my sweep generator, I aim to get a nice symmetrical S curve on the screen to show that the discriminator is balanced correctly and allowing the best performance of the radio. This is the preferred method as specified in the Hacker Hunter RP38A service manual and in fact is pretty much the defacto method for most Hacker radios, both AM and FM.
Why not check out the previous video : • Electrolytic Capacitor...
My previous Hacker Hunter video playlist : • Hacker Hunter RP38A
Test Equipment used in this video :-
Rhode and Schwartz SWM 02 sweep generator
HP 54600B Digital Oscilloscope
Many thanks for watching, keep safe and if you like the video and are not already subscribed please consider doing so. It makes me feel good and it means you won't miss out on future videos from me. - วิทยาศาสตร์และเทคโนโลยี
I have done this video just to show how easy it is to use the swept method to align FM radios.
My favorite way to do an IF alignment, as well as other work, and at my last job, many years ago, I had pulled out the sweep gen and set it up on the bench, only to find it missing when I came back from a break. I asked my boss, and he said, don't use that old junk! Which left me to the old peak and sweep the oscillator manually to verify my results.
Now that I have my own home shop, I have a spectrum analyzer with tracking generator, which is a pleasure to use! And I only answer to myself!
Браво! Много хубаво и полезно видео и добро операторско видео заснемане! Най-много ми хареса сигнал генераторът, великолепен уред! Майсторската работа е също интересен опит за всеки начинаещ в ремонта!
sweet i was not expecting such wild beardige especially on a tech tut featuring old gold hp test gear cheered me right up
Glad you enjoyed!
OMG do my eyes deceive me George you have pink hair and a pink beard? A sweep generator alignment of a radio. Then getting an s curve spot on to get the highest fidelity possible. Absolutely brilliant. I would have never thought to tune that way. Thanks for the information George.
Very interesting video. Always nice to get something that resembles the picture in the manual. 😜
Once I got the hang of using the generator it all fell into place. I wish my analogue scope hadn't died but I'm glad I had the digital one on standby.
An interesting visual representation of the process. To paraphrase Mrs Beeton, "first catch your wobbulator."
Catch the wobble, hold it in the centre and let it shake a while.
That was a great job aligning that radio and really useful for future reference. Thanks for sharing regards Chris
Many thanks Chris. will have to do more wobbly aligning in future.
Thanks George. Very interesting and informative
Starting a new project on battery radios as to repair them, done part iphones and quartz watches now radios pure hobbyist, I've started with the like of your videos and I want to try and learn from you, so I will watch all your videos and hope to learn everything from you. COLIN FROM SURREY ENGLAND 👍 👏 ❤
Great video George, thanks for sharing!
Glad you enjoyed it It was fun to do for a change rather than just peaking AM sets.
Great demo George thanks
Your turn now Graham....
Thank you George, very interesting!
Glad you liked it Tony.
Who is your beautician?....LOL
Nice work on the FM alignment George.
It's all self inflicted Bill. I think that I'm old enough to be crazy, I might as well act it!
@@GeorgeChristofi Why not, you only live once...LOL
A nice instructional video, George, good to see you finally got some colour back in to you hair...lol
Ta Muchly. Had to show it was possible. The hair has to be redone quite often to do the roots... My head is quite used to hydrogen peroxide now!
Loved the video. Thanks!
Good video. Nice and easy does it.
If you've got the gear, it makes no sense not to use it.
Who's the new lady presenter? 😍
if you can wobbulate you have to wobble. And she is probably your type!
Good stuff George. So, if I swing a signal generator around my head on its mains lead, would that work the same? Does that generator have markers? I think that's an issue for many trying to work this out in their head, not every sweep generator or wobbulator outputs markers so you might not know where 10.7 is on your scope.
if you do swing the sig gen round your head then be careful the ieee plug doesn't let go. I do have markers on the generator but the scope is to fuzzy to display them properly. Must try harder!
@@GeorgeChristofi I was watching on tablet so couldn't see the markers, Next, aligning an RA17..! :)
Nice one George, it's a shame my super-duper RF generators don't do sweep, I have to dig out one of my old HP analogue jobbies, which is a bit hit and miss. Anyway, hope you're okay. All the best from Aston.
I have to try my super duper IFR on sweep mode. it is there but the sync pulse is on a rear socket so I'm not sure if its a ramp or a gate pulse. It doesn't have markers built in either so it means having to sync it with the external marker first.
Great video but I don't understand why you lifted the capacitor to remove voltage from the back end. (4:42) What is the "back end"? AGC? Earlier in the video you mentioned that the generator output voltage needs to be set low enough as to prevent AGC from kicking in so I'm not sure what exactly you are doing in this step.
It was strange to me as well but that is what the manual calls for. I havent dived deep into the reasons at this point.
Subliminal messages are saying "Buy more Test equipment" Does this mean I've got to buy a Wobulator now?
yes... its calling you
Ahh balance and maximum amplitude.
Not sure that i would ever need to do that, but interesting never the less.
On my old vhf hunter Rp38 the f.m sounded fine, i dont mess with a working device 😀
I think the A.m i.f transformers are stacked and they have to be tuned in a particular order.
Am is ok so.... yep i leave them as is (Boring aint i lol ).
Your hair looks fine, im developing a landing spot for flys and butter flys, gimme your hair lol 😀
Is it time for fire 😀
If it works and you are happy with it then leave it alone! You tune from one end to the other in order but have to go back over yourself several times... I'm keeping the hair for now and fire may come soon.
You are a crazy pink scientist :)
It’s not hard.thanks for sharing sweep alignment .
No problem Keith. Its a pretty straightforward method once you get used to it and it does improve the fidelity a lot.
" Swept aliment" I was wating for the yard broom .not all this electronic stuff
A fellow insomniac
No we can't see anything?