WorldwideDX Amateur Radio Forums

Captain Kilowatt · #1 03-03-2012, 05:59 AM

Anyone using the Diawa CN-801HP cross needle meter? I just ordered one and it should be here the first of the week. It is the 2Kw model. I thought about the 3 Kw model but will never run that much power and thought about the error percentage being based on full scale so figured the 2 Kw model would be better for my use. I have been so wound up getting things together for my modified Larcan television amp for 6m that I forgot all about the fact I have nothing to measure over 200 watts with except for some RF current meters. They would work but then I would have to know the exact load impedance and calculate power from the RF current and do it the hard way. Besides not too sure how the presence of an RF ammeter inline would affect the line impedance at 50 MHz.

Anyway who has one and how do you like it? Is he peak reading function decent. I know there was an issue with the early models being inaccurate but that has supposedly been fixed.

Mr Clean · #2 03-03-2012, 07:20 AM

Quote:

Originally Posted by Captain Kilowatt

Anyone using the Diawa CN-801HP cross needle meter? I just ordered one and it should be here the first of the week. It is the 2Kw model. I thought about the 3 Kw model but will never run that much power and thought about the error percentage being based on full scale so figured the 2 Kw model would be better for my use. I have been so wound up getting things together for my modified Larcan television amp for 6m that I forgot all about the fact I have nothing to measure over 200 watts with except for some RF current meters. They would work but then I would have to know the exact load impedance and calculate power from the RF current and do it the hard way. Besides not too sure how the presence of an RF ammeter inline would affect the line impedance at 50 MHz.

Anyway who has one and how do you like it? Is he peak reading function decent. I know there was an issue with the early models being inaccurate but that has supposedly been fixed.

I run one and like it real well. I dont use the light real often because a friend has one and his burned out so I have a small gooseneck light on top of it. I know im lazy. You should be very happy with it.

sp5it · #3 03-03-2012, 11:29 AM

I'm using 801P. Nice, good working meter.
Needs some mods.
First mod is to change PEP circuit to be more reliable, second to see SWR in PEP mode.
If you can't find that I will post those mods later.
MIke

Robb · #4 03-03-2012, 11:41 AM

Quote:

Originally Posted by sp5it

I'm using 801P. Nice, good working meter.
Needs some mods.
First mod is to change PEP circuit to be more reliable, second to see SWR in PEP mode.
If you can't find that I will post those mods later.
MIke

Have the info for these mods?

sp5it · #5 03-03-2012, 12:48 PM

PEP mod by ZL3AG:

Quote:

When I investigated the circuit, found that the peak hold timing was acheived with a 220uF electrolytic with 2k ohms accross it. Considering the limited current delivery of a 358 op-amp, the 220uF was NEVER going to charge successfully with syllabic-rate DC drive. I replaced the 220uF with a low leakage 0.47uF capacitor and the 2k with 3MegOhm. Recalibrated and now marvellous. Nothing wrong with my Linear.

Mod to see SWR in PEP mode I'll post tomorrow, have to get that from my shack computer.
MIke

m42duster · #6 03-03-2012, 03:20 PM

I like mine very much. Very easy to read and 20 watt scale is a plus. It is very heavy and resists falling back with weight of coax.

Most owners whine because it won't show reflected power in PEP mode, no issue for me. My light still works, but I rarely use it.

JoeDirt · #7 03-04-2012, 09:22 AM

I like mine!

sp5it · #8 03-04-2012, 12:04 PM

PEP mod in the attachment.
Mike