Tech Special: ICOM IC-271A with frequency drift

Started by White Tiger, November 03, 2012, 01:00:59 am

Previous topic - Next topic

White Tiger

Anyone have one of these with a similar problem? I bought this rig and the one problem the seller mentioned was frequency drift...

I checked the Interwebs and found that one reason for this was due to ICOM using plastic trimmer capacitors in the PLL/VCO & RF/YGR circuits - the fix is to swap out the plastic trimmer caps with ceramic ones (6pf, 10pf and 20pf's). I just can't seem to find out if this is something a novice like me can do...or if I need to take it to a real radio repairman (which means I no longer got such a "deal" on the unit).

Anyone have any information/experience with this fix?

Any help would be appreciated!
If you're looking for me, you're probably looking in the wrong place.

gil

As soon as you mentioned that last time I suspected a capacitor issue... I can swap them for you Tim, but it's gonna cost you another hot chocolate...

Gil.

White Tiger

November 03, 2012, 03:36:38 am #2 Last Edit: November 03, 2012, 03:39:23 am by White Tiger
Heheh, thats right, you did! and I'll take you up on it - what a BARGAIN!
If you're looking for me, you're probably looking in the wrong place.

gil

When you buy the capacitors, make sure they are NPO types, which means more temperature-stable...

Gil.

White Tiger

I bought the ceramic ones rated with a minimum range indicated (6pf, 10pf and 20pf) - but there was no mention of NPO?

The radio arrived today, haven't tried it - except the VFO, which appears to be a bit sticky...how does your VFO turn?

If you're looking for me, you're probably looking in the wrong place.

gil

If they are the variable type, then forget what I said..

Gil.

White Tiger

Quote from: gil on November 03, 2012, 01:56:27 pm
If they are the variable type, then forget what I said..

Gil.


Hah!

Wait...which should I forget...that they should be NPO or forget the offer to swap them out!?
If you're looking for me, you're probably looking in the wrong place.

gil


White Tiger

Oh, whew...

....regarding the sticky VFO - does yours have "sticky" areas along the dial? Some owners have mentioned that the rubber gasket warps and causes the sticking - but I don't see any warping?
If you're looking for me, you're probably looking in the wrong place.

WA4STO

Tim -- the IC271A is specified to use 6amps @ 13.8v DC while in transmit mode.

Here's the manual for it -- see Page one for specs.

http://www.hurderconsulting.net/radiostuff/ic271a.pdf

I've had a number of the multimode VHF and UHF icoms.  They are just fabulous for satellite work.  Only major thing now is getting some decent 144 - 148 mHz antennas up.

Wonder how far away the local two meter repeaters are for you?

Best 73 de Luck, WA4STO

White Tiger

Quote from: WA4STO on November 04, 2012, 02:02:51 pm
Tim -- the IC271A is specified to use 6amps @ 13.8v DC while in transmit mode.

Here's the manual for it -- see Page one for specs.

http://www.hurderconsulting.net/radiostuff/ic271a.pdf

I've had a number of the multimode VHF and UHF icoms.  They are just fabulous for satellite work.  Only major thing now is getting some decent 144 - 148 mHz antennas up.

Wonder how far away the local two meter repeaters are for you?

Best 73 de Luck, WA4STO



Thanks Luck!

There are four 2m repeaters near me - between 3.9 & 4.6 miles from my location.
If you're looking for me, you're probably looking in the wrong place.

White Tiger

I read the "power supply" section which says to use at least 6 amps, and it's maximum consumption is 6amps...but it also defines the external VDC power supply as the Icom IC-PS15.

When I looked on eBay I found that exact unit - BUT - it is listed as a 20 amp power supply....?

I have an external 13.8vdc, 10 amp supply - would it simply blow the fuse if I were to try to hook it up? I'd like to see if my "Tech Special" ...actually powers up!?
If you're looking for me, you're probably looking in the wrong place.

cockpitbob

Tim,
The 10A power supply will be fine powering a 6A rig.  Even if the rig draws more than the 10A your supply is rated for, it shouldn't cook anything. 

gil

Yours doesn't have the built-in power supply? Mine plugs in directly in 110.. The only problem with it are the power switch that sometimes stops working (I leave it on and plug/unplug) and the RF gain button that seems to do nothing.. Otherwise, no sticky areas. That's probably the encoder being dirty. Easy to fix I'd expect. I really like the 271A because I didn't have to spend extra money for a tone board.. The 25W output is also a plus, compared with it's predecessors 10W.

Gil.

White Tiger

November 04, 2012, 09:35:23 pm #14 Last Edit: November 04, 2012, 09:38:11 pm by White Tiger
Gil - No, it did not come with the internal AC power supply. that was an upgrade attachement. If you got one, then you got a good deal, they are difficult to source on eBay.

Yes, I agree, overall I'm really impressed with the 271A - and that it fell within my [strike]cheapskate[/strike], budget conscious ways - while being able to give me an all-mode local communication option.

cockpitbob & WA4STO thank you both for the excellent source information regarding the power supply!
If you're looking for me, you're probably looking in the wrong place.