[HBR] questions about HBR-11

[Darrell, WA5VGO]

Joe,

No one is jumping on this, so let me throw out a few opinions.

1) The IF transformers from a BC453 work very well. Many people have used 
them successfully, so you won't be in uncharted waters if you go this route.

2)  I see no reason you can't use all three from the same BC453, although 
using all input transformers might give you a little better ultimate 
selectivity.

3) Haven't tried it.

4) They are unshielded, just like the photos depict.

5) I haven't had this problem although (just as you stated) if you are in 
close proximity to one it could be a problem.

6) The article does not call for one, but I found that adding one stiffened 
up the chassis and made a very significant improvement in mechanical stability.

The only thing I will add is, as I have stated on this reflector before, 
the hang AGC makes such a major improvement in the overall performance, I 
wouldn't think of building one without it.

Maybe some others will get in here and give their opinions.

73,
Darrell, WA5VGO




At 03:44 PM 11/17/2004 -0600, you wrote:
>Howdy. I've got a few questions about the HBR-11 that I hope you who've 
>already been down this path can answer.
>
>1) Can I use the relatively large IF transformers (85 kc) from a 
>BC453-type receiver in the HBR-11 rather than the smaller 3/4 inch 
>transformers originally specified? In other words, was size the main 
>reason for using small 3/4 inch transformers in the original HBR-8/11/13 
>article?
>
>2) The HBR-11 uses three transformers in the 100 kc IF. Can the one BC453 
>I've got provide all three transformers or do I need a second BC453 to 
>have enough of the right type?
>
>3) Has anyone made a 30 meter coil set? Are there any birdies or nasty 
>image responses when using an HBR-11 on this band?
>
>4) Pictures of the underside of the HBR-11 show that L4A and L4B (the 1610 
>kc IF transformers) do not have shield cans. Is that really how they're 
>supposed to be?
>
>5) Has anyone experienced direct IF pickup of the AM broadcast stations 
>that are now found between 1600-1700 kc? (I suppose one's proximity to 
>such a station would be the main culprit.)
>
>6) It seems the original article did not call for a chassis bottom cover, 
>is that correct?
>
>Hoping to build an HBR-11 one of these years.....  ;-)
>
>73,
>Joe K9LY
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