hi,

i just retrieved a fairly old BW 1W PLL+ that i want to put back in use.
a few questions to anyone familiar with that module:
1. the output transistor is missing: is it a 2N4427, 3866, 3553, or 2219?
2. i noticed that the toko and the orange coil former are empty; is it normal or should there be slugs in them? if yes what type and specs?
3. does anyone have the schematic, board layout and alignment procedure for it?
4. i also retrieved a 300 W pallet amp fitted with a classic SD2932 LDMOS fet; the specs for that transistor says ~19 db gain.
which theoretically means that feeding it with that BW 1W module would deliver around 50 W output, taking into account filter loss.
question is: is 1W drive power above the threshold at which that amp will start to amplify? does anyone have experience on how to push the ouput power of the BW 1W PLL+ a bit up?

txs in advance for your reactions.

I have a feeling there shouldn’t be a slug in the coil. Not sure what the big arse resistor connected to the audio input is supposed to be doing apart from impedance matching or a crude pre emphasis attempt.

As for the other questions, sorry. Don’t know enough matey.


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txs for the reaction. the "big arse resistor" isn't connected to the input but to the RF out (it's a 56 ohm load) )

Looks like it's acting as some kind of dummyload although 47 ohms is twice as closer to 50ohms.
Maybe someone was using it as a TX just to use around the house.

....The missing output is Motorola 2N4427.

From memory the 2.5t Toko S18 should indeed have 2 dot ferrite slug and the other 3.5t one either just an alloy one or without one.

You will need approx 3 or 4w to drive your 2932 but most devices good for that will probably require a bit less than 1w drive.
They are most often driven with something like a 2SC1971 or similar but just be careful not to put too much drive into that 2932 and always start lower and work your way up slowly

The 2932 was a pretty good FET at the time. I could run them at (roughly) 275 Watts with the drive from my test NRG PLL Pro III set to 4 Watts at the top end of the band.

I have one of these drivers.

Can anybody advise what display can be plugged into the 5 pin socket on the lower left, please?

Txs for the reactions.
@MIXIN: can't help you with the display as i'm missing it too.
Could you please check on your device if the TOKO transformer and the orange coil former are also empty (as on mine)?
Txs in advance.

blfsdmrf wrote: ↑Thu Mar 03, 2022 9:56 pm Txs for the reactions.
@MIXIN: can't help you with the display as i'm missing it too.
Could you please check on your device if the TOKO transformer and the orange coil former are also empty (as on mine)?
Txs in advance.

Hi mate,

This is mine, & this is how it should be as far as I'm aware; there is a slug in the Toko Transformer, and the Orange coil slug is missing.

Waow quick reply. TXS a lot mate.
One slug missing on mine then: the one in the TOKO RCL. It looks like an aluminium slug, or am I mistaken?
Do you have any parts list/schematic?
Otherwise I'll unsolder it from the pcb to possibly find some part number.

TXS in advance.

According to the info here:
http://www.geocities.ws/hellonasty.geo/bw_pll_plus.html
That toko coil is a 5.5 turn MC120
https://www.enigma-shop.com/component/h ... e-inductor
There is a circuit on that page, but no good information on the expansion connector.

blfsdmrf wrote: ↑Fri Mar 04, 2022 3:13 pm Waow quick reply. TXS a lot mate.
One slug missing on mine then: the one in the TOKO RCL. It looks like an aluminium slug, or am I mistaken?
Do you have any parts list/schematic?
Otherwise I'll unsolder it from the pcb to possibly find some part number.

TXS in advance.

Yes, the slug looks Aluminium or some sort of Alloy - but somebody more experienced than myself should come along & advise if a standard Ferrite slug will suffice.

@Yellowbeard, cheers for the link mate.

Alloy is for less inductance and ferrite for more.

Putting aluminium or copper into a coil reduces inductance - the more metal in the coil, the less the inductance, so in a tuned circuit, the frequency rises as the slug is screwed in.

Conversely, a ferrite slug increases the inductance, so screwing in a ferrite core reduces the frequency.

TXS all for the help.
From the links tthat Yellowbeard sent, I gather that L1 is a TOKO MC120 series 170 nH variable inductor with ferrite slug. On the other hand the slug looks like alloy to me on the MIXIN pic.
I keep searching and will keep you posted
PS: for your info - might be useful:
http://www.carnut.info/star-parts/pcbs/toko-winding.htm
https://www.on1bes.be/toko_tester_en.html

Couldn't find a fitting slug in my junk box for the 170 nH MC120 TOKO. Ordered a Neosid equivalent. See what happens.

In the meantime I'd like to build or buy a reliable quality (low harmonics-low spurious) 4-5W exciter kit (mono-no rds) (if possible with parts available anywhere - preferably no specialised ICs or µcontrollers if still possible nowadays).
What do you recommend? Any good schematic? Any address selling quality kits? Don't want to buy Chinese. I have found several advertisers in the Netherlands. What do you think of Dutch RF Shop kits for instance? What about the PCS Electronics kits from Slovenia?

TXS in advance for the tips.

The Dutch stuff is very good. Reliable, clean and stable. Prices are reasonable too.

The PCS gear is well designed, but tends to be quite expensive, and I'm not sure that his gear is available as kits these days.

Both the above use pre-programmed ICs to drive their PLL chips, so your "no specialized ICs" requirement won't be met!

TXS a lot for the advice Albert. I'll go for the Dutch stuff then.