[Boatanchors] National HRO-500

[peter markavage]

You can do a search on the boatanchor and National archives to review
past discussions on the HRO-500. Most of the time the lack of sync lockup
can be traced to gold contamination on the bandswitch contacts. Cleaning
carefully with deoxit can help alleviate the problem. Also remember that
the bandswitch also turns a switch on the top of the chassis through a
pulley/cord. Proper physical alignment is a must. I generally rock my
bandswitch through all the positions at least once a week even when I'm
not using the receiver. The contact switch wiping helps keep the switch
contacts clean. Strong front-end overload has always been a problem with
this receiver. SSB distortion has also been reported on a number of these
receivers. ER magazine also ran several articles on this receiver
incuding some mods.

Probably one of the more highly over-rated receivers as far as over-all
performance.

Pete, wa2cwa

On Fri, 30 Dec 2005 09:53:54 -0500 flood at Krohne.com writes:
> Greetings,
> 
> First of all Happy New year!
> 
> A HRO-500 followed me home yesterday.  Aside from a dent in the 
> lower back 
> corner the unit is very good cosmetically.  It powers up but the 
> synth. 
> only locks up at 3.5 and 29.5 MHz.  I have the manual and am 
> starting to 
> study it but was wondering who the resident HRO-500 experts are.  
> Boy this 
> is a lot different than anything I've ever worked on before but at 
> least I 
> can still see the parts without a microscope and I don't have to 
> worry 
> about sticking my finger on several hundred volts of B+.  Is there a 
> 
> better list for help with this beast?   It is after all solid-state 
> and a 
> lot lighter than my other toys. 
> 
> Also, is there anyone left here in the northeast who repairs these 
> in case 
> I get hopelessly lost? 
> 
> John Flood KB1FQG
> TASC Department
> KROHNE, Inc
> 7 Dearborn Rd.
> Peabody, MA   01960
> Tel.:  978-535-6060 / 800-356-9464
> Fax:   978-535-8180