The British Caving Association

I am in the process of building the PIC Controlled cave radio found on the http://www.vollok.nl site. I found the transformers, had boards made, and have built the boards using the toaster oven method. However, I have found some issues in the files on this site and have emailed those mentioned in the project and have not received a reply. I have some questions and would like to find someone who is familiar with this project. Any help would be appreciated!!!!
Danny Britton
kb4tep
dlbritton@comcast.net

Hi Danny,

Apologies for the slow response. The http://www.vollok.nl site seems pretty old and a bit dysfunctional and I'm having difficulty in finding the files you talk about. In particular, the 'General Info' and 'Projects' buttons don't appear to function (and the 'Links' button works in IE and Chrome but not in my version of Firefox!). Did you get the board designs and schematics from this site, or from somewhere else?

In the meantime, I'll try to find alternative contact information. Erwin and Herman have both subscribed to the CREG Journal at some point, though I'm not sure if they are current subscribers. I'll check and get back to you.

Best regards
Rob Gill

That's the valid URL: http://www.vollok.nl/projects/pic_controlled_caveradio/ with all the data.

I wrote to Danny an email with the answers to questions he had but some issues may be also valid for others: From my notes:
1. there is a problem with the board, one connection is missing and should be kynar'ed from pin9 of the U8 to the pin 13 of the U4 (the Q-line).
2. I changed the value of R14 from 15k as in schema to 10k because the divider U3 was oscilating with a saw-wave instead of square.
3. I added a big rectifiing diode on the power supply line - it prevent from putting the power supply in wrong polarisation.

All the filters should be properly adjust as described in the HeyPhone service manual.

Thanks Adam, very helpful.

There is a lot to be said for a build-able and straightforward design.

Any idea how many of these PIC controlled HeyPhones have been built?

Best regards
Rob

Rob Gill wrote:Any idea how many of these PIC controlled HeyPhones have been built?

At least two in Netherland and at last two by me here in Poland

Rob, maybe there is a time to re-design the HeyPhone and use a uC for generating some signals? That will cause simplification of the construction and a reduction in needed parts.

Some more info - because I'm building one more set I get some new experiences.
The main issue is that the part list is really out-of-dated and some parts have wrong values or does simply not exist (eg. U18/U19).

1. TOKO filters are only available from JabDog company.
2. The main transformer can be found in Feryster company. The valid set is EF20-K-H-8P-SS bobbin and EF20/10/6 ferrite 3C90 core.
3. 8MHz 5V rectangular clock module can be only found via Aliexpress, eg. here.
4. Because pair of capacitors needed for a filter C27/C28, C29/C30, C39/C40 and C44/C45 are not easly avaliable, I changed the values and solder in parallel the values: 100p + 100p + 220p + 10p which sums to 430p and is the same as on the schema pair of 100p + 330p.
5. As above, the same was with the triples of resistors: R29/R30/R31, R60/R61/R62 which were solder as followings: 7k5 + 470k + 10k which sums to 487k5 ans is the same as on the schema triple of 430k + 56k + 1k5
6. And as above, the same with the pair of resistors: R35/R36 and R79/R80 which new values are: 0R + 200k which are more than suggested 18k + 180k but with the tolerancy of 5% it's ok.
7. R110 is 10k, R111 is 22k - wrong values were on the part list.
8. TDA7052A (U16) in DIL8 is hard to be found (I found it at very small shop with old electronics), instead the SMD version with a conversion board from SO-8 to DIL-8 can be solder.
9. R13 (220ohm) need to be high-power. Two relays consumes quite a lot of power so I changed R13 to 3x560ohm in parallel because single resistor overheats.
10. The main transformer was wound by: 10x two (in parallel) DNE0,5 (primary) and 10x two (in parallel) DNE0,5 + 66x DNE0,32 + 33x DNE0,32 + 33x DNE0,32 + 33x DNE0,32 (secondary). Each layer separated by transformer-type polyester adhesive tape.

I think that before someone decide to build this set, it's better to re-design the whole board with the newer elements.

Hi, my name is Roberto and I´m from Spain. I have Friends who likes speleolgy and how I know something about communications they ask me If I would be able to build a radio.

I´ve read about heyphone and I would like build a pair of them, thanks to CREG, in particullary Jhon Hey (RIP). Nevertheless I´ve read this topic about pic controlled and I have some doubts, is posible that I´m not understand english like I would like.

What´s the different with heyphone? I understand that with this radio you have audio communications, moreover you could control a Surface radio in VHF?
Maybe I´m wrong but in pictures this radio is easier to build than heyphone?
Here http://www.vollok.nl/projects/pic_controlled_caveradio/ is type that for costsaving its frecuency is 86´956Khz, you know why? Nevertheless I understand that they can communicate with Heyphone in 87Khz, it´s right??
How much money cost build this radio or heyphone? 100,200,300€ ??

I´ve more doubts, but I need to know this for start to build.

Thanks in advance.

I hope my english is enough