[ARC5] BC-453 or R-23(*)/ARC-5 on 600 meters...

[Geoff]

Id say that an up and down variation is due to line voltage stability and 
not the receiver. Time to regulate all voltages and use as low as possible 
to maintain performance. This includes filaments at the low side of the 
bogey spec.

Low power SOLA and other CVT's are cheap on fleabay and elsewhere and they 
also clean up most line noise. I use one on my TS-940 and TS-950SD with each 
bench having its own master switch so the CVT's arent left on and unloaded.

Carl


----- Original Message ----- 
From: "Bill Cromwell" <wrcromwell at gmail.com>
To: <arc5 at mailman.qth.net>
Sent: Sunday, August 03, 2014 5:18 PM
Subject: Re: [ARC5] BC-453 or R-23(*)/ARC-5 on 600 meters...


> Hi Les,
>
> Somebody in the thread mentioned WSPR. That has to be zero +/- 2.5 Hz (as 
> reported to me after queries. For transmissions on that mode you would 
> want even tighter control as the stations are fractions of 1 Hz apart. 
> Drifting very far would QRM you neighbors. If you go to all that trouble 
> it can take all night just to claim a valid contact - call sign and 
> location! I also understand that a computer data file is required so the 
> "radio" can look up the info to verify it. Maybe that is a different, very 
> fussy mode. I still ain't there. I do play some digital modes and computer 
> based DSP (digital signal processing) and that really helps with noise 
> reduction and other audio filtering tasks. With the DSP methods there is 
> little to no ringing with bandwidths under 100 Hz. Even with a filter 
> setting of less than 100 Hz the BC-453 stays close enough to keep the 
> incoming signal in that passband. I'm suggesting that some of them might 
> stay within the +/- 2.5 Hz. To be sure you measure it that close - how 
> much does the timebase in your counter drift? I'm just an amateur with the 
> old, bad attitude - "good enough is good enough". I can copy NDB 
> transmitters and some CW here and there all night long on my BC-453 and 
> R23. When I put the audio up on a 'waterfall' display I can see the 
> frequency drifts up and down a few cycles but I have to look close. I 
> don't know how much is the VFO, how much is the BFO, nor how much is the 
> computer or soundcard timebases. So there is another reason I am not 
> interested in the "too fussy" modes. Some people get their enjoyment from 
> splitting frog hairs and I think it's cool. But I ain't there. I hope this 
> helps.
>
> Let us know what you find.
>
> 73,
>
> Bill  KU8H
>
> On 08/03/2014 04:16 PM, Leslie Smith wrote:
>>    Hi Ken,
>>    I'm surprised to read your words "they lack the necessary stability
>>    for 'extreme accuracy' modes.
>>    What degree of stability do you require?
>>    I'm going to attach my old-fashioned frequency counter to the L.O. to
>>    measure drift in my ATA beacon band receiver.
>>    My set "settles down" very quickly after it's switched on - SSB is a
>>    breeze with a simple converter in front of the "R-23".  (It's an ATA
>>    not R23!)
>>    I'm particularly interested because I run my set from a 60V regulated
>>    B+ supply, and (at that voltage) the 'tubes' run cool.
>>    (Cooler than Bob Dylan)
>>
>>    The limit to sensitivity for the beacon band receivers lies in (a)
>>    atmospheric noise.
>>    If it's "there" an ATA set will hear it on MF/HF.
>>    The designers from the mid-30's knew their stuff (and all done with a
>>    slide-rule too!)
>>    They were really "hot".
>>
>>    73 de Les Smith
>>    vk2bcu at operamail.com
>>
>>
>
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