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Old 5th Nov 2017, 10:32 am   #41
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

As is usual with coils working at VHF they tend to be self supporting without a former. Expanding the turns (stretching the coil) will result in a higher frequency coverage. I think using a GDO to at least get the frequency coverage right would be a first step.

Regards
Symon.
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Old 5th Nov 2017, 10:40 am   #42
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi mole42uk.

From your original thread back in 2014, I see that your kit was supplied with what looks like matrix board. The kit that I ordered depicts a PCB in the illustrations on ebay.
Re the coils, I would have thought that both coils should be of the same diameter . The transistor super regen that I built used coils of the same diameter mounted end on to each other. The spacing between the two coils being quite critical as I remember.

Regards
Symon.
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Old 5th Nov 2017, 12:26 pm   #43
Neil Purling
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

I wish Phillips210 all the luck in the world in making this kit. I think that member is going to need it.

If you got actual broadcasts I would suggest you go out and buy a lottery ticket, because Lady Luck hath smiled upon you.
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Old 5th Nov 2017, 3:05 pm   #44
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Ha Ha, Thanks, I think I'm going to need the luck with this project by all accounts. Expert member G6Tanuki does however think it should work. I think the biggest problem is going to be the frequency response of the 1A2.

I can't help thinking that I may have been swizzled buying that kit
Oh well, it's only money!

Regards
Symon
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Old 5th Nov 2017, 11:13 pm   #45
Neil Purling
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Phillips210: I have seen the version with the PCB.
We do want to find out what happens. You have some experience in making and arranging the coils.
I don't know exactly how the circuit would render audio from a FM signal, to know whether the choice of device is valid.

Is the kit still in transit?
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Old 5th Nov 2017, 11:57 pm   #46
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Yes Neil, it's only just been ordered so it's anyone's guess when it will arrive but probably within the next four weeks. I am looking forward to the challenge (but not the frustration of a big disappointment) and will report back here.

In the meantime if there's any more advice it will be much appreciated. I shall also be reading up on super regens.

Regards
Symon
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Old 11th Nov 2017, 2:17 am   #47
JohnBG8JMB
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Just found this thread. There is a vast amount of info on super-regen rx and the associated fremodyne rx on
http://members.iinet.net.au/~cool386/index.html

Tempted to have a go - it's 60 years since I last made one, using a 954 acorn valve {PW, I think] It worked...but tuning was by adjusting a slug tuned ex-telly coil.

73
John G8JMB
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Old 11th Nov 2017, 10:23 am   #48
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Thanks John for the link, it look a very interesting site.

Regards
Symon.
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Old 21st Nov 2017, 1:12 am   #49
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Well, the kit arrived but on checking through the contents there are a number of parts missing and also there are no instructions whatsoever not even a circuit diagram. I've sent a message to the seller and hope the problems can be resolved. It doesn't bode well and I'm less confident about a successful outcome to this project. I guess I'll have to be patient and may be a little more optimistic!

Attached a pic of the incomplete kit. One good point is that it has an excellent quality PCB. The valve has green corrosion on the pins, not a good sign.

Regards
Symon
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Old 21st Nov 2017, 6:07 am   #50
TonyDuell
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

I knew of somebody who (many years ago) would buy a Heathkit and then hide the manual. They would then work out how to make a <whatever> from the supplied components and do so. This was before PCBs as well...

Perhaps that's what you are supposed to do here. Work out how to make a radio on that PCB.
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Old 21st Nov 2017, 10:02 am   #51
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

Yes, it shouldn't be too difficult to work out where everything goes as the PCB has component references and values printed on it plus the circuit diagram is generally available anyway. It still doesn't excuse the fact that there are missing parts namely the two important coils, a resistor, a knob and jack socket (no real big deal). A circuit diagram is depicted in the illustration so by rights should have been supplied.

Looking at the PCB, it seems slightly odd the connection points for the two coils. They would appear to be mounted end on to each other as expected but the leadouts effectively crossover each other. Also, it would seem these coils are mounted on the reverse (solder side) of the PCB. It certainly looks to be quite a challenge to get that circuit working.

Regards
Symon.
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Old 25th Nov 2017, 3:39 pm   #52
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

I had a positive response from the seller after contacting him/her and providing a pic of the incomplete kit. A replacement kit is going to be sent out so hopefully it will be complete this time.

Looking again at the PCB, I still find it difficult to understand why the leadouts of the two coils need to cross over each other when a simple redesign of the PCB would overcome this. Then, something occured to me, what if one coil is mounted on the normal (component side) of the board and the other on the solder side? That would possibly explain the reasoning for planning the four connections in that fashion. The coils would then be parallel to each other (with the PCB in between) rather than mounted end on to as in the transistor super regen circuit that I built. It's something I'll be pondering on. Maybe if the replacement kit has decent instructions then the mystery will be cleared up.

I'm looking forward to the challenge of building this super regen circuit. Will update in due course.

Regards
Symon.
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Old 25th Nov 2017, 6:26 pm   #53
Neil Purling
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Have the instructions put up on here & someone will be able to read them & see if that particular placement of the coils is mentioned.
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Old 11th Dec 2017, 12:06 am   #54
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

I am still waiting for the replacement kit to be sent so hopefully it will arrive shortly.

Talking about the type of coupling between the two coils in earlier posts got me thinking about further coupling arrangements. I came across these https://www.ebay.co.uk/itm/A-Pair-Su...gAAOSw9hdZ5xZf superregenerative transmitter/receiver modules on ebay. It's of interest the way in which the two coils in transmitter circuit are coupled. They're mounted at 90 degrees and at close proximity.

Regards
Symon.
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Old 23rd May 2018, 12:39 pm   #55
december251906
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Did you ever build this kit? I'd like to know if it actually works. - Thanks
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Old 28th May 2018, 7:07 pm   #56
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

Sorry for the delay in replying, I just noticed your post. I haven't yet built the kit as I've had a few setbacks this year so it's been put on hold for a while. I do intend to build it over the coming months and will report back.

Regards
Symon.
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Old 14th Oct 2018, 9:43 pm   #57
Neil Purling
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Did anything come of your efforts with this kit? I still see them for sale.
How many people have been stung?
Assuming that the thing is basically beyond the ability of most people and does not employ a device that will work at 90Mhz or above.
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Old 15th Oct 2018, 11:25 pm   #58
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi

I had good intentions of building the kit but I'm sorry to say that I haven't been able to as this year I've had a huge amount of work commitments and family difficulties. Also, I'm in the process of dismantling my workshop to make way for a larger unit which I hope to have completed before Christmas. I am currently able to so some electronics assembly/repair work in my home and if I am able to find the time I will make a start on the kit.

I will definitely report back in due course.

Regards
Symon
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Old 16th Oct 2018, 10:30 am   #59
Neil Purling
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

I suspected that there was no way that the kit could be made to work very well, given the need for precision at frequencies around 100 Mhz. This is not helped by the pathetic build instructions.
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Old 16th Oct 2018, 10:07 pm   #60
Philips210
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Default Re: Chinese 1A2 Super Regenerative FM radio kit

Hi.

I'm inclined to agree that it is doubtful the 1A2 valve will work well at around 100 MHz.
I wonder if any of the experts on here can say with confidence if the circuit will work or not. I bet Hugo (member Argus25) would know if this circuit is viable.

Regards
Symon
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