Look what neigbours kids did!

[Albert H]

Remember - with an indoor aerial you'll lose ~90% of your signal, and you won't be able to get a vertical aerial up there!

I ran a few Watts into a shortened vertical at the higher end of the MW band, and got surprisingly good daytime coverage, but the earth had to be really good. I also tried a helical, with a helical counterpoise. It was difficult to get a good match, but when I did, it really travelled! There was a "topband" design for this kind of helical in the "Tech Topics" column of RADCOM back in the 90's. I just scaled it up to get it to 1386kHz (which was dead quiet in the daytime).

[FMEnjoyer]

That 35€ one might be nice to start.

I think that aluminium tube dipole would be best choice, easiest way to hide one cheap 100W 50Ohm resistor. We all live very near of very active military base/airport, I dont want that these kids get busted.

Do not ever use this near a military facility.

https://www.amateurradioshop.nl/webshop ... uwkit.html

Warped sense of responsibility on here from some condemning everything Chinese, more a naive political ideology than based in truth than suggesting that total and utter VFO rubbish.

It might be worth reflecting for a moment. If every item of electronics Made in China that in in an average Brits house was removed.

There would be no electronic devices left in it.

[Persona Non Grata]

Does vero/stripboard work ok at VHF frequencies? I thought there might be too much stray capacitance between the tracks ?

[EFR]

That 35€ one might be nice to start.

I think that aluminium tube dipole would be best choice, easiest way to hide one cheap 100W 50Ohm resistor. We all live very near of very active military base/airport, I dont want that these kids get busted.

Do not ever use this near a military facility.

https://www.amateurradioshop.nl/webshop ... uwkit.html

Warped sense of responsibility on here from some condemning everything Chinese, more a naive political ideology than based in truth than suggesting that total and utter VFO rubbish.

It might be worth reflecting for a moment. If every item of electronics Made in China that in in an average Brits house was removed.

There would be no electronic devices left in it.

They are nowdays building their rigs by themself, I didnt even order it.

Filtering, more filtering.

Im pure HF idiot, not interested by FM broadcasting.

Does vero/stripboard work ok at VHF frequencies? I thought there might be too much stray capacitance between the tracks ?

Sort of, even old deadbug style might be better.

[radionortheast]

Does vero/stripboard work ok at VHF frequencies? I thought there might be too much stray capacitance between the tracks ?

I’m not sure why an oscillator wouldn’t work if you make the other tracks round it ground?. The pll part would, I suppose alot to go wrong only 1 error will make it not work, a pcb is better, for a filter it will work ok, you can make the adjecent tracks ground, add the capacitance you want.

[shuffy]

In the late 70's / early 80's the ubiquitous back-of-Practical-Electronics 2 transistor VHF "bugs" were on Veroboard and worked OK (and in no small part contributed to me getting into RF building!)

So it "works" but, you've no way of knowing what the stray inductances and capacitances are, so you can't use it for anything critical and increasing the complexity of such a circuit on Veroboard is a non-starter due to feedback issues and lack of a ground plane. So yes ugly or dead bug can be better in that respect. Lots of pirate rigs were done this way back in the day. Granted, there were some shockers.

Even prototyping RF I wouldn't use Veroboard not even at HF (sorry Albert!). Call me what you like but these days it's so cheap and quick that I've started going straight to JLC with prototype designs which I know will need at least another iteration. Veroboard NOT!!!

[EFR]

I etch my own pcbs, faster than wait 3 weeks from JLCPCB

[shuffy]

I etch my own pcbs, faster than wait 3 weeks from JLCPCB

Not sure whereabouts you are EFR but for basic PCBs delivered to the UK, I'd be disappointed if it took longer than a week after them approving the design.

I too made my own PCBs for years using CAD/inkjet trannies/photo resist and then etching/cleaning/drilling (for through hole). Still do for simple prototypes. Definitely quicker, I can knock a board out in under a day if I get my finger out. But certainly not cheaper, all things considered. Then as time went on I was trying to make smaller and smaller boards with SMDs and you just can't take advantage of the size without going multi-layer. Trying to do double sided PCBs myself - and actually getting small things lined up without being able to do proper vias - was a right pain in the arse! So I guess I reached the point where I personally couldn't prototype what I wanted to end up with and therefore the fab house had to become part of the lifecycle.

Don't get me wrong, despite starting out in full time commercial electronics (moved out of that sector pretty soon) I consider myself a relative numpty and I find it mind blowing what these fab houses can do. 6 layers for the same price as 2? Flippin heck! And that's nowhere near the limit.

Coincidentally I've put a JLC order in this afternoon, around 3PM which would be after close of play in China. Nothing fancy, a small double sided board and didn't pay for any extras or more than the basic delivery options. It got reviewed and went to prodution quickly (this time) so I'll report back.

[Albert H]

I gave up etching my own boards for exactly the same reason (that and the ferric stain on my garage floor!). It's now so cheap and easy to use the Far Eastern PCB manufacturers. If I'm in a rush, I can get up to 4-layer boards from a local manufacturer, but they cost a fortune! I needed some audio processing boards in a hurry recently, and they cost exactly 52 times the price I would have paid at JLC. The fastest I've received boards back from JLC is 6 days, but in this instance we needed the processors "yesterday"! We got them overnight, and spent the whole of the next day populating them, testing and calibrating them, and bolting them into their 19" boxes. It was lucky that I keep a stock of "THAT" ICs!

[shuffy]

Coincidentally I've put a JLC order in this afternoon, around 3PM which would be after close of play in China. Nothing fancy, a small double sided board and didn't pay for any extras or more than the basic delivery options. It got reviewed and went to prodution quickly (this time) so I'll report back.

My boards arrived. Sparing all the detail, I put the design in on Monday afternoon (UK time). By Weds morning it had been packed and was awaiting collection by the courier, and they got it here today (Fri) at 2.30PM. That's a shade under 4 days end to end. Haven't examined the merch as of yet.

The whole thing came to around £24. That's 5 boards, which is the minimum. The production cost was $2, I think it should have been $4 but some offer or other was applied. There's a couple of quid fees or whatever but for small orders like this the bulk is courier costs and these can go up and down.

[EFR]

Best what I have get from JLC is about two weeks

[sinus trouble]

The problem i find with "Chinese Products" is that there is little regulation on quality standards!

I am often bombarded with Temu, Ali Baba and even Ebay gear! None are confirmed as safe!

European components by law need to be certified as safe!

RS, CPC and Farnell are guaranteed to work within specification!

[Novaro]

Any opinions on this traditional circuit i found on eBay;
I ordered also the red pcb pll. I will fit the components i already have and order some I don't.

[EFR]

On older pcb, looks like You have mounted that coil on wrong point? Looks like You need to solder center tap to it and mount it that hole.

Never seen these boards IRL.

[Novaro]

On older pcb, looks like You have mounted that coil on wrong point? Looks like You need to solder center tap to it and mount it that hole.

Never seen these boards IRL.

Thank you for your help and for replying to my post. I have not received the traditional! one until now. The picture is from product description. Its a complete kit with components and instructions. When i start building it i will follow your advice about the coil mounting.

[Krakatoa]

The red one with the MC145151 looks good, like it has a chance to work fine if built and adjusted properly. Is a kind of asian version of the MPX96.

The kit with the bakelite board, seems like a kind of school project, a massive board with big and sparsely distributed components.
It is an FM bug, with electret microphone input.

[Albert H]

The one with the 145151 uses the Sharp LB3500 prescaler IC. These are getting rare!

The circuit is OK (I know who designed it), but the output is only about 50 - 90mW. It was designed to give a very quiet carrier.

[Novaro]

The one with the 145151 uses the Sharp LB3500 prescaler IC. These are getting rare!

The circuit is OK (I know who designed it), but the output is only about 50 - 90mW. It was designed to give a very quiet carrier.

Could you explain us if there is a difference when is used 145151 instead of say tsa5511 on a driver unit?
Is there any advantage for designs like NRG PLL or the one i posted versus the rdvv, pkbee, pira or similar designs? Except the fact they don't need a pic and software programming. Basically there is a huge list of designs with the same principals and probably with similar behaviour circuits but very few other approaches.

[Albert H]

The advantages of the 145XXX series of ICs are:

• Simple programming (in binary) without any PIC or Atmel programmed IC needed.

• Use of cheap, easy-to-get reference crystals

• Reliable and quiet phase detectors (some with twin outputs)

• Accurate and reliable lock detection

There are a couple of (minor) disadvantages - they tend to be more expensive these days, they take up more board area, and they need an additional prescaler to get the signal sample down into the range of the ICs presettable counter.

[Way back in the mists of time, I used the MC145106 (really cheap - they were used in CB rigs) and used the reference oscillator output multiplied up to just below Band II. I then used the PLL itself to generate low frequency modulated signals which were mixed with the multiplied crystal then filtered to give a 1-chip Band II switch-tuned PLL! Dave (an old friend, now sadly deceased) came up with the idea, and we had a run of about 20 exciters built this way. They were really tiny, and fitted into a small tinplate box.]

I still prefer the simple 74HC CMOS logic-based PLL, and back when we were making lots of rigs, we were buying tubes of the ICs very cheaply. They made for a slightly larger board layout, but they were unbeatably cheap, and worked flawlessly. Early on, we used to fit all the programming diodes, then snip one leg of the diodes we didn't want. Later versions of the boards used solder blobs to select the diodes! Buying the ICs in 100s, they were really cheap. I found a box of 100 good quality 4 MHz crystals for about £6 which were ideal for the reference. Some versions of the PLL used to 4046 for the phase comparator, but later ones used a combination of two bistables and NAND gates, which gave really good results when filtered by a dual op-amp loop filter, and accurate Lock / Unlock outputs too.

[rigmo]

The one with the 145151 uses the Sharp LB3500 prescaler IC. These are getting rare!

The circuit is OK (I know who designed it), but the output is only about 50 - 90mW. It was designed to give a very quiet carrier.

do you heave schematic? possible rework?