Hammerhead project I started yesterday

[Micheal]

Hi guys ...I have started th hammerhead project (wish me luck ) ...yesterday I made the PCB
...today I have just finished drilling the holes....

quick question..in the instructions it says to use .25watt resistors is it ok to use 0.5 watt resistors.

[Qiaozhi]

Hi guys ...I have started th hammerhead project (wish me luck ) ...yesterday I made the PCB
...today I have just finished drilling the holes....

quick question..in the instructions it says to use .25watt resistors is it ok to use 0.5 watt resistors.

A 0.5 watt resistor will be physically larger than a 0.25 watt, but if it fits in the space provided then no problem, as the resistance value is the same.

[kt315]

0.5 watt resistors have more wide pins... bad decision, especcialy for small printing contacts PCB has. try to find 0.125 or 0.065 watt resistors.

[Micheal]

In the hammerhead instructions pdf rev1.5 page 8...
Parts list ....R10 & R50 what is the correct value please ...and has someone got a picture of there HH with the etched board completed and working so i can see If I am doing the right thing ....

[Micheal]

I am having trouble with the parts below they are either not on the parts list or not on the pcb parts placement diagram page 12 fig 18... I am building the VCO version can somebody please help with this

1....C16 is in the parts placement diagram but not in the parts list(opt1)

2....Q10 is in the parts placement diagram but not in the parts list(opt1)

3....C10 is in the parts list but not on the parts placement diagram
(where does this C10 1000uf capacitor go on the board)

4....R49 is in the parts placement diagram but not in the parts list(opt1)

5....R22 is in the parts placement diagram but not in the parts list(opt1)

6....R10 I think is 1ohm is this correct ?

7...D2 & D3 is in the parts placement diagram but not in the parts list(opt1) do I put them on or leave them out (if I put them on are they 1N4148 diodes)

[Carl-NC]

1....C16 is in the parts placement diagram but not in the parts list(opt1)

C16 is not used.

2....Q10 is in the parts placement diagram but not in the parts list(opt1)

Q10 is not used.

3....C10 is in the parts list but not on the parts placement diagram
(where does this C10 1000uf capacitor go on the board)

C10 has to be placed on the back side of the PCB. I bend the leads so it lays down.

4....R49 is in the parts placement diagram but not in the parts list(opt1)

Not used.

5....R22 is in the parts placement diagram but not in the parts list(opt1)

Not used, replace with a short.

6....R10 I think is 1ohm is this correct ?

Correct.

7...D2 & D3 is in the parts placement diagram but not in the parts list(opt1) do I put them on or leave them out (if I put them on are they 1N4148 diodes)

The parts lists has "D1-D4," which means "D1 through D4," including D2 & D3.

Be sure you are looking at the Opt1 schematic instead of the general (all-inclusive) schematic. It should specifically say "Option 1" on it.

- Carl

[Micheal]

Hi Carl thanks very much for your reply...I am going from the HHv1p5.pdf
I was frantically trying to work things out. I am pretty new at all this so please bare with me...I am working off HHv1p5.pdf page 12 figure 18 I cannot work out where to connect the C10 to and its polarity.I have attached the pcb diagram from your booklet...can you please mark on the picture where to connect C10 to....Thank you

[Micheal]

here is the pcb option1 below

[Micheal]

...

[Micheal]

Also Carl R8 is in the parts placement diagram but not on the parts list ,should I leave this one out aswell ?If it is to be put in what is the value please

[Carl-NC]

R8 is shorted. You are looking at the all-inclusive parts diagram, not the Option 1 version. Print out the Option 1 PDF and it will be much clearer.

- Carl

[Micheal]

Hi there Carl ...thank you for your help and its all coming along real well ....
Thank you for making me aware I was on the wrong diagram ,very sorry
I am still not sure where C10 goes or connects to or if it is off the board can you please help me where it is to go...and also I have added a diagram below
with to things in it that im not sure about...they are marked ?1 and ?2


I am assuming that?1 is just a little jumper
and ?2 has nothing there just left empty is this correct please ......

The other thing I would like to ask you is
------- IC1 is a ICL7660
-------IC3 AND IC4 are both 79L05
-------Q3 ...is a IRF740( i have a irf 540 can I use this here or not)
are there are other options or equivalent and more commonly available parts that can be used for those becuase I am having a real hard time sourcing them around Sydney way...

[Micheal]

Sorry about all the pictures and questions...
I think C10 goes here am I right or wrong Carl(picture below)

[Carl-NC]

You are right about ?1 and ?2, and about C10. 79L05 should be easy, look for slight name variations like LM79L05. Same for the 7660... look for any kind of "7660". IRF540 will work fine.

- Carl

[Micheal]

thanks Carl...ill be recieving the 2 parts on Monday and put them in along with all the pots...In the mean time I have a 2 mono coils for my Garrett xl500 which i would like to use
...here is the details for the coils



Garrett XL500 7"coil 149.5uH 1.2(ohms)

garrett XL500 large 33cm coil (I dont know the uf value but it is 1.2ohms aswell)
What damping value resistor will I use ,do I just change the R11 to use these coils or is there more to be changed.
can I use an external pot for R11 for when I use different different coils or is this not a good idea.