Today's Message Index:
----------------------
1. 03:06 AM - Re: flummoxed ! (Craig Payne)
2. 03:44 AM - Re: Nanchang Flap Problem (Mark Pennington)
3. 05:58 AM - [Non-DoD Source] Re: Circuit breaker size for pitot heat? (Rob Rowe)
4. 07:17 AM - Re: Nanchang Flap Problem (Byron Fox)
5. 07:24 AM - Re: Re: flummoxed ! (Byron Fox)
6. 07:56 AM - Re: Nanchang Flap Problem (Mark Pennington)
7. 02:07 PM - Russian VHF Antenna Diplexer Design and how it impacts ignition noise (Bitterlich, Mark G CIV NAVAIR, WD)
Message 1
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Blitz,
I not a betting man (except for the stock market). Check your plumbing.
Craig Payne
Message 2
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| Subject: | Re: Nanchang Flap Problem |
Mr. Fox
In your original scenario with the hissing in the rear valve while
operating the front valve and looking at the colored coded diagram on
Doug's site it would seem that "one way" the air could escape through the
rear valve would be if the diverter / check valve was open for some
reason. Dirt, bad spring etc.
The spring loaded diverter valve is spring loaded shut while operating from
the front cockpit and the rear in the neutral position. Passing air
through the diverter valve and to the flap actuating cylinder. Pressure
from the rear flap valve opens this diverter valve so you can operate from
the rear cockpit through the diverter valve.
The pink ball in the diagram is seated into the "V" of the valve symbol and
the spring symbol is pushing the pink ball against the "V" while operating
from the front cockpit.
If the pink ball was not seated in the "V" air would escape from the rear
valve while applying pressure to the system from the front. If you
determine that is the source of the problem I know Doug has your new part
on hand I just purchased a complete set for my CJ
Hope this helps, if I am incorrect on this maybe someone could give us a
hand.
Mark Pennington
N621CJ
On Fri, Jul 13, 2018 at 1:19 AM, Byron Fox <byronmfox@gmail.com> wrote:
> I'm completely flummoxed !
>
>
> 1. It began this way. Several days ago, I noticed that when the front
> seat flap handle was put in the down position, air came hissing out of the
> backseat flap valve at a great rate. The latter of course in the neutral
> position.
> 2. With the flap extended, air hissed merrily away until I put the
> forward flap handle in the neutral position. Works, but not right. Right?
> 3. Put the forward flap handle up. Flap retracts as normal.
> 4. So what's with the aft flap valve? With the forward handle neutral,
> the aft flap handle works normally up and down.
>
> So today, I did the following:
>
> 1. Thinking there must be something wrong with the aft flap valve,
> (although only about three months since purchased new from Doug), I removed
> it and capped off the three air lines running into it with 1/8 NPT caps.
> Thereby, by-passing the aft valve completely.
> 2. Now to test the fix. Put the forward flap handle down, and the flap
> extends smartly.
> 3. Put it up and NOTHING HAPPENS! The flap just stays down. WTF!
> 4. Called and whined to Doug. He was perplexed too, but suggested I
> replace the forward flap valve with the newer one I removed from aft.
> 5. Did it. NO LUCK. Same result. Goes down, but won't come up.
>
> Any thoughts? I'm baffled. I keep staring at the CJ's pneumatic diagram
> and rereading Craig Payne's air system guide, but no bulb goes off over my
> ever balding head.
>
> Many thanks,
>
>
> --
> ... Blitz
>
> Byron M. Fox
> 80 Milland Drive
> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
> Mill Valley, CA 94941
> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
> 415
> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
> -307-2405
>
>
Message 3
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| Subject: | Re: [Non-DoD Source] Re: Circuit breaker size for pitot heat? |
Mark,
Thanks for your useful insight as always ... I don't have an original antenna to
inspect, short of stripping the one out of my aircraft, and neither the analyser
kit even if I did. So if you have an original antenna to hand and an analyser
that would be very helpful to better understand empirically what is actually
going on.
As you point out this was designed as a 'splitter' and not for the purpose of reducing
RF interference into the original Baklan radios. But from practical experience
(identical kit installs, by 40+ year avionics guy with same loom design
and materials) it does appear to help some newer 8.33k replacement radios that
are more sensitive to RFI.
I agree from Fourier principles the square wave RFI 'hash' will run across the
band at odd harmonics that rapidly diminish in magnitude with increasing frequency,
hence the high pass takes most of the lower frequency 'energy' out that
probably helps the RF amp from being overwhelmed by transients. The original Baklan
radios may not have needed this, but replacement radios seem to find it
beneficial.
The attached schematic (extracted from a Russian doc) shows how simple the circuit
is, that relies on the RF cable impedance to provide the 'R' component of
the filters. Annoyingly no component values are given, nor on the original schematics,
where it just refers to it as being factory manufactured, so custom made.
Given this is only a first order filter the roll-off slope is gentle, and to avoid
attenuating the aircraft comms band, the Fc might be as low as 30Mhz. It will
be interesting to see what your analyser results yield.
Hence finding a higher-order in-line diplexer alternative, as you've come up with,
could be a big help and as I don't have the kit, or radio expertise, to provide
definitive answers I really value your skills here.
Rob
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=481632#481632
Attachments:
http://forums.matronics.com//files/baklan_antenna_filter_385.jpg
Message 4
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| Subject: | Re: Nanchang Flap Problem |
Thanks for responding, Mark.
I did remove and check both of the aft diverter valves. The springs are good
and both bench checked with high pressure air from my scuba tank. They seal
well.
Blitz Fox
415-307-2405
> On Jul 13, 2018, at 3:43 AM, Mark Pennington <pennington.construction.inc.
1@gmail.com> wrote:
>
> Mr. Fox
>
> In your original scenario with the hissing in the rear valve while operati
ng the front valve and looking at the colored coded diagram on Doug's site i
t would seem that "one way" the air could escape through the rear valve woul
d be if the diverter / check valve was open for some reason. Dirt, bad spri
ng etc.
>
> The spring loaded diverter valve is spring loaded shut while operating fro
m the front cockpit and the rear in the neutral position. Passing air throu
gh the diverter valve and to the flap actuating cylinder. Pressure from the
rear flap valve opens this diverter valve so you can operate from the rear c
ockpit through the diverter valve.
>
> The pink ball in the diagram is seated into the "V" of the valve symbol an
d the spring symbol is pushing the pink ball against the "V" while operating
from the front cockpit.
>
> If the pink ball was not seated in the "V" air would escape from the rear v
alve while applying pressure to the system from the front. If you determine
that is the source of the problem I know Doug has your new part on hand I j
ust purchased a complete set for my CJ
>
> Hope this helps, if I am incorrect on this maybe someone could give us a h
and.
>
> Mark Pennington
> N621CJ
>
>
>
>
>
>
>
>> On Fri, Jul 13, 2018 at 1:19 AM, Byron Fox <byronmfox@gmail.com> wrote:
>> I'm completely flummoxed !
>>
>> It began this way. Several days ago, I noticed that when the front seat f
lap handle was put in the down position, air came hissing out of the backsea
t flap valve at a great rate. The latter of course in the neutral position.
>> With the flap extended, air hissed merrily away until I put the forward f
lap handle in the neutral position. Works, but not right. Right?
>> Put the forward flap handle up. Flap retracts as normal.
>> So what's with the aft flap valve? With the forward handle neutral, the a
ft flap handle works normally up and down.
>> So today, I did the following:
>> Thinking there must be something wrong with the aft flap valve, (although
only about three months since purchased new from Doug), I removed it and ca
pped off the three air lines running into it with 1/8 NPT caps. Thereby, by
-passing the aft valve completely.
>> Now to test the fix. Put the forward flap handle down, and the flap exten
ds smartly.
>> Put it up and NOTHING HAPPENS! The flap just stays down. WTF!
>> Called and whined to Doug. He was perplexed too, but suggested I replace t
he forward flap valve with the newer one I removed from aft.
>> Did it. NO LUCK. Same result. Goes down, but won't come up.
>> Any thoughts? I'm baffled. I keep staring at the CJ's pneumatic diagram a
nd rereading Craig Payne's air system guide, but no bulb goes off over my ev
er balding head.
>>
>> Many thanks,
>>
>>
>> --
>> ... Blitz
>>
>> Byron M. Fox
>> 80 Milland Drive
>> Mill Valley, CA 94941
>> 415-307-2405
>>
>
Message 5
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Checking the plumbing will be today=99s hanging-upside-down-in-the-coc
kpits exercise, Craig. How I hate it.
Blitz Fox
415-307-2405
> On Jul 13, 2018, at 3:05 AM, Craig Payne <yakman285@gmail.com> wrote:
>
> Blitz,
>
> I not a betting man (except for the stock market). Check your plumbing.
>
> Craig Payne
Message 6
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| Subject: | Re: Nanchang Flap Problem |
Good Luck if I think of anything else I will reach out.
Lets us know what you find.
Mark
On Fri, Jul 13, 2018 at 10:16 AM, Byron Fox <byronmfox@gmail.com> wrote:
> Thanks for responding, Mark.
> I did remove and check both of the aft diverter valves. The springs are
> good and both bench checked with high pressure air from my scuba tank. They
> seal well.
>
> Blitz Fox
> 415-307-2405
>
>
> On Jul 13, 2018, at 3:43 AM, Mark Pennington <pennington.construction.inc.
> 1@gmail.com> wrote:
>
> Mr. Fox
>
> In your original scenario with the hissing in the rear valve while
> operating the front valve and looking at the colored coded diagram on
> Doug's site it would seem that "one way" the air could escape through the
> rear valve would be if the diverter / check valve was open for some
> reason. Dirt, bad spring etc.
>
> The spring loaded diverter valve is spring loaded shut while operating
> from the front cockpit and the rear in the neutral position. Passing air
> through the diverter valve and to the flap actuating cylinder. Pressure
> from the rear flap valve opens this diverter valve so you can operate from
> the rear cockpit through the diverter valve.
>
> The pink ball in the diagram is seated into the "V" of the valve symbol
> and the spring symbol is pushing the pink ball against the "V" while
> operating from the front cockpit.
>
> If the pink ball was not seated in the "V" air would escape from the rear
> valve while applying pressure to the system from the front. If you
> determine that is the source of the problem I know Doug has your new part
> on hand I just purchased a complete set for my CJ
>
> Hope this helps, if I am incorrect on this maybe someone could give us a
> hand.
>
> Mark Pennington
> N621CJ
>
>
> On Fri, Jul 13, 2018 at 1:19 AM, Byron Fox <byronmfox@gmail.com> wrote:
>
>> I'm completely flummoxed !
>>
>>
>> 1. It began this way. Several days ago, I noticed that when the
>> front seat flap handle was put in the down position, air came hissing out
>> of the backseat flap valve at a great rate. The latter of course in the
>> neutral position.
>> 2. With the flap extended, air hissed merrily away until I put the
>> forward flap handle in the neutral position. Works, but not right. Right?
>> 3. Put the forward flap handle up. Flap retracts as normal.
>> 4. So what's with the aft flap valve? With the forward handle
>> neutral, the aft flap handle works normally up and down.
>>
>> So today, I did the following:
>>
>> 1. Thinking there must be something wrong with the aft flap valve,
>> (although only about three months since purchased new from Doug), I removed
>> it and capped off the three air lines running into it with 1/8 NPT caps.
>> Thereby, by-passing the aft valve completely.
>> 2. Now to test the fix. Put the forward flap handle down, and the
>> flap extends smartly.
>> 3. Put it up and NOTHING HAPPENS! The flap just stays down. WTF!
>> 4. Called and whined to Doug. He was perplexed too, but suggested I
>> replace the forward flap valve with the newer one I removed from aft.
>> 5. Did it. NO LUCK. Same result. Goes down, but won't come up.
>>
>> Any thoughts? I'm baffled. I keep staring at the CJ's pneumatic diagram
>> and rereading Craig Payne's air system guide, but no bulb goes off over my
>> ever balding head.
>>
>> Many thanks,
>>
>>
>> --
>> ... Blitz
>>
>> Byron M. Fox
>> 80 Milland Drive
>> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
>> Mill Valley, CA 94941
>> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
>> 415
>> <https://maps.google.com/?q+Milland+Drive+Mill+Valley,+CA+94941+415&entry=gmail&source=g>
>> -307-2405
>>
>>
>
Message 7
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| Subject: | Russian VHF Antenna Diplexer Design and how it impacts ignition |
noise
Rob,
I have changed the subject line, since the topic is not IAW the original.
Concur on all observations and comments that you made.
Yes, I can locate and sweep the original Russian antenna, after I manage to gen
up some connectors and so forth, but in the end what is the real sense? We already
know the intent of the design. The premise is that their design was shunting
low frequency energy thus possibly reducing the amount of hash that was
being fed into the VHF's radio first stage RF amplifier. I hate re-creating the
wheel, (unless I am being paid to do so) and I doubt you really want to either,
especially if there happens to be a cheap alternative, and there is. "Cheap"
being a subjective term I admit.
The Comet and Diamond Antenna sites contain specs and alternatives for an experiment
like this. One has a male PL-259 pig-tail input with two SO-239's coming
out of the Diplexer for A/B Port outputs. So there are a few options when it
comes to how to interconnect whatever you choose.
We are looking at a 45-50 dB reduction of hash in the frequency range of 1-30 Mhz
or so, (and for the uninitiated that's 10 to the 5th power) and that is where
I believe the majority of noise is going to be (we agree again on that one).
I have seen prices as low as $60 (U.S. Dollars) for something like this, and
a 50 ohm load is simple to construct for the low freq. port.
Of note is the fact that I have used these devices myself, (hence how I know about
them) mainly with some ham radio equipment. They work extremely well and
meet specifications. So 60-70 dollars will allow you to put one of these in line
and see if it does indeed reduce spark plug noise. If it does, you've come
up with an idea that will impact the whole community, since a lot of us use
Dennis's auto spark plug conversion, which on occasion has been known to increase
spark plug noise just a tad. It's a great idea, and the premise has basis
in theory and factual experience.
Mark
________________________________
From: owner-yak-list-server@matronics.com [owner-yak-list-server@matronics.com]
on behalf of Rob Rowe [yak-list@robrowe.plus.com]
Sent: Friday, July 13, 2018 8:57 AM
Subject: Yak-List: [Non-DoD Source] Re: Circuit breaker size for pitot heat?
Mark,
Thanks for your useful insight as always ... I don't have an original antenna to
inspect, short of stripping the one out of my aircraft, and neither the analyser
kit even if I did. So if you have an original antenna to hand and an analyser
that would be very helpful to better understand empirically what is actually
going on.
As you point out this was designed as a 'splitter' and not for the purpose of reducing
RF interference into the original Baklan radios. But from practical experience
(identical kit installs, by 40+ year avionics guy with same loom design
and materials) it does appear to help some newer 8.33k replacement radios that
are more sensitive to RFI.
I agree from Fourier principles the square wave RFI 'hash' will run across the
band at odd harmonics that rapidly diminish in magnitude with increasing frequency,
hence the high pass takes most of the lower frequency 'energy' out that
probably helps the RF amp from being overwhelmed by transients. The original Baklan
radios may not have needed this, but replacement radios seem to find it
beneficial.
The attached schematic (extracted from a Russian doc) shows how simple the circuit
is, that relies on the RF cable impedance to provide the 'R' component of
the filters. Annoyingly no component values are given, nor on the original schematics,
where it just refers to it as being factory manufactured, so custom made.
Given this is only a first order filter the roll-off slope is gentle, and to avoid
attenuating the aircraft comms band, the Fc might be as low as 30Mhz. It will
be interesting to see what your analyser results yield.
Hence finding a higher-order in-line diplexer alternative, as you've come up with,
could be a big help and as I don't have the kit, or radio expertise, to provide
definitive answers I really value your skills here.
Rob
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=481632#481632
Attachments:
http://forums.matronics.com//files/baklan_antenna_filter_385.jpg
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