RELIC HAWK

[Max]

Max,
What are/is your battery(s)/supply level? I have found that some of the circuits REALLY do not like marginal voltage (especially the oscillator).

In that same area, I am still trying to find out what their "low battery warning" sounds like (the manual fails to tell you this).

Regards,
J. L. King

Hi,
my supply is at 12V +- 1%. Inside circuit I have 2.48V at TL431 regulator... and thus my GND level is at 4.96V.

So, considering GND as reference I have -4.96 for V- and +7.04 for V+.

The low battery thing I don't understand well still now... I tried to lower the voltage to see what happens but cannot hear anything... maybe there's another mistake in schematics in that part too.

In some military units the low battery gives a constant, steady tone... so prevent you using e.g. detector when in a minefield in such conditions.

I think ML used the same strategy used in that military units... but till now I didn't pay much attention to battery checker... must look at it better.

Kind regards,
Max

[KingJL]

I've made a simulation till comparators... and got about same phase I get from measures...

.... So, the PCB/circuit is like expected, no errors and timing is the same as from schematic we have.

This confirms problem is somewhere else... maybe at coil ?

Max,
What are/is your battery(s)/supply level? I have found that some of the circuits REALLY do not like marginal voltage (especially the oscillator).

In that same area, I am still trying to find out what their "low battery warning" sounds like (the manual fails to tell you this).

Regards,
J. L. King

[Fred]

O.T.

This is completely off topic but if anyone need a really tiny RS232 converter, here it is.
Just done this for GPS experiments but may be used for many applications, so i post it here
Regards,
Fred.

[ivconic]

When tracing routes using posted photos, do not be confused with pin assignments....it is not usual!

[Max]

schematic update

Hi,
here's revision 1.9.

Corrected the "f" line according to the discovery made on Musketeer board.

Kind regards,
Max

[ivconic]

No Tiktak, i am far away from any work in my workshop, for now. Resting and doing nothing.

Yes it is transistor for sure (is this deja vu or what??). It says "SR51" at both machines i had; RH and Colt. Later i found out it is BSR51 (guess they were lazy to print "B", or paint saving??) .
So if it is BSR51 than BC517 is proper replacement, although there are other transistors to do same job there...
But...than you still must use earphones. If speaker is nedeed than audio must be modded. Guess Bulgarians solution at Coinseeker could be a starting point...

[Max]

Hi,
Ivconic told us it is no J-fet, just transistor.He knows what he says.

Max, what transistor did you use for audio output? BC517?

regards,
Fred.

Hi,
yes... about... it's a C517, Japan made.

Do you think at its higher gain as a problem ?

Kind regards,
Max

[Fred]

MAX , I think The Relic Hawk Has used Armstrong-tickler configuration for oscillator to elimate Harmonics. So the smt "unknown transistor" is special purpose , and hidden somewhere , or on the back of the circuit board must be tiny smt inductor for tickler coil. Could this be late 1990s V-Flex technology without the "V" ......I think the Musketeer used this circuit also !!!.....Let us know what you think especially if your checking oscillation at tx circuit again.....Take Care.........Eugene

Hi,
Ivconic told us it is no J-fet, just transistor.He knows what he says.

Max, what transistor did you use for audio output? BC517?

regards,
Fred.

[Max]

MAX , I think The Relic Hawk Has used Armstrong-tickler configuration for oscillator to elimate Harmonics. So the smt "unknown transistor" is special purpose , and hidden somewhere , or on the back of the circuit board must be tiny smt inductor for tickler coil. Could this be late 1990s V-Flex technology without the "V" ......I think the Musketeer used this circuit also !!!.....Let us know what you think especially if your checking oscillation at tx circuit again.....Take Care.........Eugene

Hi Eugene,
to me the oscillator is working good with BC327 and BC337 there. I get more than 16Vpp at coil... that's what expected I think.

I don't know if ML have some special configuration hidden about oscillator... what I know is that it works like we have in the schematics... just particular transistor are employed to gain oscillations and stability.

Anyway... I'm a bit disappointed by disc... not oscillator. I expected problems at oscillator when I saw schematic the first time... but sure I wouldn't expect bad disc from RH.

Just another puzzle... probably there's something wrong in schematic not already spotted.

Kind regards,
Max

[Fred]

Just received the components today

SuperRH is back on tracks!
Regards,
Fred.

[amtech2005]

RELIC HAWK

MAX , I think The Relic Hawk Has used Armstrong-tickler configuration for oscillator to elimate Harmonics. So the smt "unknown transistor" is special purpose , and hidden somewhere , or on the back of the circuit board must be tiny smt inductor for tickler coil. Could this be late 1990s V-Flex technology without the "V" ......I think the Musketeer used this circuit also !!!.....Let us know what you think especially if your checking oscillation at tx circuit again.....Take Care.........Eugene

[Max]

update... about phase

Hi,
I've made a simulation till comparators... and got about same phase I get from measures...

for example:

in measures I get 79.2° for GEB at fully CCW and I get from simulations 82.48° there...

You see... not big differences... about 3-4°... maximum I've found is around 7° about disc that happens only when geb pot is fully CW.

So, the PCB/circuit is like expected, no errors and timing is the same as from schematic we have.

This confirms problem is somewhere else... maybe at coil ?

Kind regards,
Max

[tiktak]

Hi

Hi,
Max.
S-M-L all the same all rock stable!
I loved most M.Other are specialized I think.
So something is still wrong there!
But first we need original coil copyed!Ivconic did you have time to finish your copy?And if so what are datas?
Thanks

[Max]

Hi,
I've made some tests in S and L modes...
results: in S mode detector is similar to M mode, same detection range, average with same problems.

In L mode I think it's like a motorcicle... cause of the hum-buzz the speaker gives at output.

Don't know why but in L mode device works very bad... probably is not tuned well I think. Lot of this buzz sound, kind of a ramp of noise...

Not much interesting apart that in S mode seems works a little better.

Kind regards,
Max

[Max]

Max, just for grins reverse your RX coil leads. See what effect that has. A coil 180 out would still null out ferrite (GB) but would have very erratic DISC.

If that has no beneficial effect, then consider that this RH might need the coil null adjusted while looking at output from preamp to overcome the ~10mV fed from the RX through the 4.7M to the preamp.

Kind regards,
J. L. King

Hi,
yes, right, I will try reversing leads, it worked many times in past. Also about preamp the 4M7 resistor is something there isn't in many other designs... good to pay attention to it and its related effects.

At now device works, I can null ferrite totally in disc mode, I can null it at few cms in all-metal, detection is enough for coil dimensions only real problem is disc that's unreliable when targets are far... 15cm or more from coil.

I mean, you have not large beeps at far distances on e.g. iron targets, just fast/short beeps but that will be confusing on the field, cause are similar to good targets beeps at greater depth.

I've changed the LM393 yesterday... using 393AN kind but change nothing, problem is not there.

I'm looking forward to find the possible source of problems but so far I cannot spot it right.

Also, till now I've made all tests in "M" mode that's default for RH, but I need to try device in "S" and "L" modes too to see what happens.

Kind regards,
Max