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Author Topic: HW-7 mods  (Read 1604 times)

Offline PA1FJ

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HW-7 mods
« on: January 13, 2015, 20:36:29 UTC »
Does anyone have experience with the modifications of the Heathkit HW-7.
Specially the Better ears for HW-7.

72 Fred PA1FJ
73 Fred PA1FJ

Offline KC8AON

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Re: HW-7 mods
« Reply #1 on: January 14, 2015, 12:30:31 UTC »
I had an HW-7 once and it was the worst receiver I have ever heard.  Looked at some of the mods but looked like more trouble than it was worth so I sold it.  Have had 2 HW-8's and they are a great little rig but still not up to todays standards.  My little elcheapo MFJ 40 meter Cub will work circles around either of the Heathkit rigs !  Do yourself a favor and save the HW-7 as a collector only, and get something better to put on the air that you can enjoy !

Offline PA1FJ

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Re: HW-7 mods
« Reply #2 on: January 14, 2015, 15:50:46 UTC »
The HW-7 is for me more a hobby project than a Transceiver where I join make QSO's, since I have better sets for such as the FT-817.

72 Fred PA1FJ
73 Fred PA1FJ

Offline KC8AON

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Re: HW-7 mods
« Reply #3 on: January 14, 2015, 20:53:13 UTC »
It would definitely make a good hobby project !  Lots of room for improvement, but from what I've read, its basically a major rebuild to make it useable.  I'm sure if you do some google searching, you would find lots of info !  Good luck my friend.

73,
KC8AON

Offline PA1FJ

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Re: HW-7 mods
« Reply #4 on: January 20, 2015, 15:29:26 UTC »
HW-7 modified SBL-1 Mixer, 40673 as LO buffer.
Works great better than original, and that for 25 Euro!!
Really QRP!

72 Fred PA1FJ
73 Fred PA1FJ

Offline KC8AON

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Re: HW-7 mods
« Reply #5 on: January 22, 2015, 13:34:00 UTC »
Anything would be better than original on an HW-7 - the one I had was horrible on receive!

Offline N8XEE

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Re: HW-7 mods
« Reply #6 on: February 26, 2015, 03:46:28 UTC »
Anything would be better than original on an HW-7 - the one I had was horrible on receive !

It's actually no worse than any other DC receiver...  The sensitivity is just fine.  It's the selectivity that's a problem, as it's very wide.  The easiest (and least invasive) mod is to add an outboard audio filter between the rig and your headphones.  Mine has 6 steps that go from 2,500 Hz down to about 100 Hz.  I usually run it around 400Hz, which is plenty narrow for all but the most crowded band conditions.  The Four State QRP Group sells a kit for about $20.  It has a 50dB notch at 200Hz.  There are other kits that range from about the same up to just under $100.  Well worth the money.
Current callsign - KC3RN

Offline WB3T

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Re: HW-7 mods
« Reply #7 on: May 07, 2015, 00:09:20 UTC »
I think the HW-7 has gotten a bad rap. Mine works fine with a few simple mods and an outboard audio filter. Rebuilding the whole receiver section is NOT necessary! Here's mine with a DSP unit, but the Four State SCAF filter does just as well.

https://www.youtube.com/watch?v=EpPGC2XQT4A

A description of the mods can be found here: http://radiowb3t.homestead.com/heathkit.html

Good luck!
Bob, WB3T