PDA

View Full Version : Icom R-71a mods !



John Wilke K9RZZ
03-01-2007, 05:44 AM
It's been just too quiet here, so here's the big plans for my DX equipment. :D

My main radio for AM DXing has been the Icom R-71a which I purchased online already modified with narrower filters in the first and second IF positions.

http://www.universal-radio.com/used/u150a.jpg

The BC filter has been removed and the pre-amp activated on AM BC as well. It's also got the Nardo RAM board and Kiwa audio upgrade. I really like it, it hears really well right down to WWVB at 60 khz, but it's showing it's age and is now deaf below 8mhz, so it's time to make some repairs:

http://www.dobe.com/wts/funk/R71A.txt

I'm also going to try the detector upgrade for improved audio recovery:

http://www.geocities.com/n2cbu/Icom/R71MODS/AM-Detector.htm

I have finally located that Schottky diode for that swap here:

http://www.newark.com/jsp/Semiconductors+&+Prototyping/Discretes/AVAGO+TECHNOLOGIES/5082-2835/displayProduct.jsp?sku=09F7154

Just recently I acquired a SECOND R-71a off of eBay - completely stock. It works okay, but it does get pretty noisy on the AM BC band so it will have to be operated on to bring it up to snuff. I figure as long as I'm in there, I will perform the above mentioned upgrades for audio, BC filter, pre-amp and will try the Kiwa filter module too:

http://kiwa.com/kiwa455.html

That Premium Filter Module looks real tempting!

http://kiwa.com/fmp1.gif

So that's the plan. Now that I've talked the talk, I'll have to walk the walk.

:laughing:

So stay tuned for updates as the project develops.

:p

John K9RZZ

John Wilke K9RZZ
03-06-2007, 12:45 AM
Well, now I'm debating whether I should go with International Radio filters (INRAD) instead of the Kiwa. I can't find any prior comparisons online however. More investigation to follow.

:confused:

John K9RZZ