[Moon] 432MHz LNAs current state of the art.

[qq363gud at voice.ocn.ne.jp]

Hello Conrad, 

It is very interesting to read your post on 432 VLNA's, and I agree to your comment on this band. 
It should be a fascinating EME frequency, even if there would be some QRM from illegal mobile operation 
by track drivers in JA, and some clock noise from modern electric equipment in urban areas world-wide. 

Recently I talked with my friend Hide JR1EUX, who is an semiconductor engineer, about HA8ET VLNA-432 using SAV541+.

He is wondering what is the real purpose of the input resonator, because it's selectivity should not be so 
sharp as he simulated, and the sharp selectivity of HA8ET VLNA-432 depends on the output BPF. 
(A fine article on HA8ET VLNA-144 is published in DUBUS 2019/4, and in TECHINIK XVIII.)

So my friend designed a wide and strait strip line for the SAV541+ input circuit, which realize 
(at least in his simulation) a good selectivity as well as low loss.  
We had the same technic in the metal cavity LNA era. 

I hope we would be able to show you the next VLNA for this band soon. 

Unfortunately Gyula Nagy HA8ET passed away this year, and we cannot ask him directly. 
His son deals with remaining VLNA's of each band, but most of them are already out of stock, and he 
is not professional to answer the question in this field. 


Mike JH1KRC 




----- 元のメッセージ -----
From: "Conrad PA5Y via Moon" <moon at moonbounce.info>
宛先: "moon at moonbounce.info" <moon at moonbounce.info>
Cc: "'pe1itr. com'" <moon-net at mailman.pe1itr.com>
送信済み: 2021年09月27日 午後 9:51
件名: [Moon] 432MHz LNAs current state of the art.

> Hello I currently use a VLNA 432 from HA8ET or a VHF Design EME LNA, both use the SAV541+ and claim to have noise figures of <0.3dB. I have several of these LNAs and measure between 0.28 and 0.35dB which is very good but of course how much can I really trust a Noise Com NC346A and an Mauri Microwave (Alitect) 2075 noise figure meter? I have an R&S FSV with the FSV-K30 Noise figure application at work and the correlation between the systems is good.However I seem to be 1dB down on what I expect from celestial sources. Maybe it is antenna pattern and noise ingress. I am using a PGA103+ as a second stage with a very good band pass filter in between.I would like to know what the current state of the art is for 432MHz LNAs. If I can be sure of my first stage LNA then I can start looking at other factors. I have small system and every scrap on RX counts. There are more QRP stations on 432 than I am accustomed to on 144MHz, I would like to have a shot at hearing them.To those who are suffering noise on 144 you could do worse than give 432MHz a try, it is an excellent EME band. It is so nice to hear an even undisturbed noise floor again!73Conrad PA5Y_______________________________________________Moon mailing listMoon at moonbounce.infohttp://moonbounce.info/mailman/listinfo/moonJoin eQSL.cc https://eqsl.cc/qslcard/Index.cfm