IV+ zener diode question...MARKO!! HELP!!!

Discussions regarding our FM transmitters, DX reports, antenna designs, problems...

Moderators: Sir Nigel, Nina, pcs, 5r, phpBB2 - Administrators

Post Reply
User avatar
ad
New registered user
New registered user
Posts: 3
Joined: Sat Mar 25, 2006 11:39 pm

IV+ zener diode question...MARKO!! HELP!!!

Post by ad »

MARKO

At least it always used to be Marko who was so helpful there. I just now finally got around to assembling MAX IV+. It was ordered a while ago and might have been one of the first to ship. There were a few part substitutions, no big deal and I figured them all out, but I want to check on this last one. The bill of materials specifies D2 as 12V Zener and D3 as 11V Zener. I received a 9.1 and an 11 (C9V1PH and C11PH). Part of me is guessing that these parts just set up a reference difference and I should just put the higher voltage in D2 position (D2=11V, D3=9.1V). But another part of me wonders if the C9V1PH just got in the wrong bin by mistake.?????

The only other part substitution I want to check on is that I received a 4MHz xtal in the LCD kit, identical to the one in MAX IV+ kit, instead of 6.4MHz as in instructions for LCD...problem?????

Last question. I broke thermistor R38 (NTC 33k) trying to move it closer to the heat sink, stupid, I know, I have to order new part by mail and it will be a couple weeks and I don't want to wait to test MAX IV+. Can I substitute a normal 33K resistor temporarily and be careful with heat??

Thanks in advance, you have always been very helpful in the past

Aurora
User avatar
pcs
Site master
Site master
Posts: 3132
Joined: Fri Jan 18, 2002 1:00 am
Location: Radio Land
Contact:

Post by pcs »

You're right with zener diode.
Quartz is ok too, no problem there.

Regarding the NTC resistor, replace with ordinary resistor,
but you'll loose temperature protection.

Bolt the heatsink to the metal enclosure to dissipate heat!
Best regards,
Marko - PCS Electronics
--------------------------------------------------------
Turn your PC into a FM radio station!
http://www.pcs-electronics.com
fax +386 4 2316 128
User avatar
ad
New registered user
New registered user
Posts: 3
Joined: Sat Mar 25, 2006 11:39 pm

Post by ad »

YES!!!

Marko, you are a rock star!

It,s Saturday man...Don't they give you weekends off in Slovenia?

OK, so the 9.1V goes in the 11V spot and the 11V goes in the 12V spot. This sets up a 1.9V reference which ends up having something to do with the voltage applied that controls output power. Oh, for the days of MAX1 when you printed schematics. By the way, very well done on MAX PRO IV+. If it does what you say (I should know in a few minutes now) it truly is a worthy sucsessor to PRO 1, of which I have built several.

Thanks again Marko, best customer support in the world!

Aurora
Sir Nigel
Moderator
Moderator
Posts: 334
Joined: Fri Nov 28, 2003 5:07 am
Location: us.gif
Contact:

Post by Sir Nigel »

ad wrote:It,s Saturday man...Don't they give you weekends off in Slovenia?
Marko works too much. :lol:
-empty-
Post Reply