LULU kits are available on EBAY

[ff]

Stretchyman in the UK has just released his LULU kit.  This is for the RF deck only.  You will need an audio amp and you'll have to wind a modulation transformer.  If you lack appropriate transformer iron a T200-26 iron powder core from Amidon or CWS Bytemark will do the job.

http://www.ebay.com/itm/131528950533

I have bought from Stretchy several times and he is on the up and up.  His boards tend to be high density so newbs should pass but if you have some building experience, this is probably the easiest and most painless way to get a decent signal on the air.

[Antennae]

From what I can understand in the Ebay description, it sounds like the kit comes with the modulating toroid.

[ff]

Yes it do.  Are you considering this Antennae? 

[Antennae]

Oh man, this thing looks great. Its small, looks fairly easy to solder together, has plenty of power. From my judgement, it looks like it will be a classic.
I bet if it were posted in the "For Sale" forum it would go like hot cakes.   

Can you tell me what frequencies the LULU can transmit on?  The ebay ad sounds a little like it has a wide range. I searched and didn't find anything specific.

[John Poet]

It says from 5-7 mHz.

Appears to be tunable for a 30 kHz range, around the crystal frequency that you supply.

[Weighted_Cube (Ali)]

I was about to say if you needed the modulator for it to function properly.

Currently, they are sold out but he said that he is building more.

[ff]

Oh man, this thing looks great. Its small, looks fairly easy to solder together, has plenty of power. From my judgement, it looks like it will be a classic.
I bet if it were posted in the "For Sale" forum it would go like hot cakes.   

Can you tell me what frequencies the LULU can transmit on?  The ebay ad sounds a little like it has a wide range. I searched and didn't find anything specific.

Antennae, I must caution you that Stretchy's boards ARE small.  They are small and VERY densely populated.  They are NOT "easy to solder".  There are several surface mount components also.  They are not for the novice.  Having said that, Stretchy's kits are high quality and well designed, and he is VERY helpful with his customers.  I've built three of his projects over the last couple of years so I know of what I speak...

[RNI]

Great thread! I'm looking to transmit my show on my own and was put onto this thread. I've emailed him but I can't solder to save my life and with shakey hands it wouldn't be the beat idea to do.

I've asked if he can supply and build it up.

It would be great

[ff]

Great thread! I'm looking to transmit my show on my own and was put onto this thread. I've emailed him but I can't solder to save my life and with shakey hands it wouldn't be the beat idea to do.

I've asked if he can supply and build it up.

It would be great

I'm glad to hear that you're attempting to have Stretchy do the build for you.  I can't stress it enough that although high quality, Stretchy's kits are HARD to build - very compact.  If he will build it for you then your satisfaction is assured.  I have been mulling the idea of making Lulu kits available myself - easier to build kits - but having PCBs made is expensive and I need to see some real interest before I make an outlay.  Good luck with yours RNI!   

[Stretchyman]

HI there, Stretchy here, I have found where you’re all hiding at last!!
OK, yes tis I who’s been selling the LuLu kits on FleaBay and the odd PWM modulator.

A little history, past and present………….

I’ve been into building RF circuits for over 40 years but only in the past 10 have I got fully up to speed and I’m now a self-employed RF Test engineer, have my own company in the U.K. and do this RF stuff for fun; have a fully functioning lab to 6GHz but much prefer to piddle around with stuff that’s useful and easily reproducibly with the minimum of fuss.

OK, having read thru’ the previous comments I just want to be clear on what I can build / supply etc as there seems to be some confusion!

I am currently selling a nearly fully built kit which will ONLY require the addition of a XTAL, it’s loading caps (22-47pF?) and a trimmer (22or47pF).
The ‘LuLu’ esq design is class E and therefore reasonably efficient (80% if using 12V) and will give 10W of carrier power (can be used as a C.W. TX) and will modulate to 4 times this (approx. 40W if using ‘Conventional’ modulation tranny techniques).

So that’s 40W from a design no bigger than your thumb!

Having a PCB means just plonking the bits on and soldering up, no thought required, well a few coils need winding if you are building it yourself but I think this is the fun part.

Yes it’s small, all parts are thru’ hole but if you prefer SMT there are pads on there too, just use a magnifier, I do!

I can supply the mod tranny core but don’t really want to wind the tranny for you (such fun!) but can if you REALLY want me to (would be part of a fully built and tested TX) and I don’t build any modulators as there’s no need to as they’re available from CHINA for cheap, again can supply but ONLY as part of a fully built and tested system..
The modulators (class D amps) are bomb proof and just turn off if upset and have not blown one up. These are infinitely better than the ‘TDA’ things of old. They will push out 20W@12V so ideal in this design.

As a complete transmitter solution there is NO other design out there that is as simple or as efficient.

I’ve also got loads of other designs but they’re not ready to release yet.

A, PiC driven DDS board (for those $5 DDS boards from China); 2 banks of 16Ch accessed via HEX sw, will be (eventually) user programmable but first release will have the 16 frequencies pre-programmed. I can’t write software and have had so many people say they could do this for me and 2 years on I’m still waiting for my latest ‘friend’ to produce something!

B, Push pull Class E, with PWM on a single PCB, have some early boards done and they work well giving 30W@12Vand 120W@24V. Still needs some work tho’.

C, 8 Cree Sic 3rd generation FET class E amp with 8 drivers, should achieve 2KW+at 120V, bit scary so keeping that one on the back burner for a while.

D, MiNi PWM for any transmitter, half the size of my last board with a single FET for 200W max any voltage from 10V to 50V.
For you folk stuck with 12V, there’s many a Voltage booster on Ebay, just get a decent 150W one to boost the 12V to 24V, $3.56 when I last looked (27/10/15)
The voltage boosted PWM thing may seem complete overkill and overly complex but both PCB’s are about the same size as Class D amp (modulator) and altho’ you still need a filter on the O/P of the PWM it’s small, doesn’t get hot or give any frequency related problems or weigh a ton (remind you of something!). Oh and you can modulate the carrier to ANY level, so 150% not a problem.

OK, that’s my rant over for now!

I’ve got a new batch of LuLu style PCB’s just in so if you want one contact me on here and you will get a decent discount.


I want to hear these things on the air, not roasting a dummy load in my lab!!

Please let me know if you want a full kit, or built.

Don’t forget you will have to supply your own Xtal.

I can’t really sell a fully working transmitter as that would be illegal!!

Please free to ask any questions

Regards from the U.K.

Stretchy

 

P.S. Have attached a pic of the top layer. I've left plenty of options for the Oscillator, Xtal/Ceramic wi/wo VXO option.

I don't think they're particular difficult to build, if you can solder, you can build it. It's masked so you can't short out adjacent pins.

 

[Stretchyman]

Now Complete, i.e. Built & Tested with Xtal (6295-6930KHz), Modulator and mod tranny!

Contact me direct.


Stretchy.

eBay item number:

131595757554