Date   

Relays

Colin Ranson
 

Et al,

 

Further to the relay thread – it got me thinking.  Deep in the depths of my junk shed I found a long forgotten diecast box containing an aborted 70cm mast head pre-amp project from about 1980.  In it I discovered a 12v Amphenol relay part 554-6542, (the 42 is a bit indistinct but think it’s right) N connectors with the common at 180 degrees to NO/NC.  Now this relay is not very big, the main body is 13 x 13 x 50mm and the N socket bodies are ‘narrowed’ to fit.  Another partially visible number seems like 11092-3. Out of interest the device was a BFT95.

 

I have checked it out and it seems fine in the RX receive path of my system.    I would love to use it in a MHPA, I really don’t expect to be able to use much more than 100w (sequenced system) before EMC problems.

 

An internet search has revealed no information but I a sure there are people out there with old catalogues ?

 

Best regards and thanks....

 

Colin de G8LBS.

 

 

 

Sent from Mail for Windows 10

 


Re: Ecoflex 15 Plus at 2,400Mhz

Dave Cawley G4IUG
 

 
 
I think you guys need to read the whole thread again ?  There was a surprising conclusion.
 
YMMV
 
Dave 


Re: Denis G3UVR SK

Keith
 

Back in my G6HHV and G0HEI days Denis was a source of a good 23 cms signal, he was my first ever contact on the band, we were about 7 miles apart !
The sight of him arriving on top of Cyrn Yr Brain, outsiders Llangollen, in his red Ferrari, on rutted dirt tracks is something I will never forget.
In my days as a DJ, 1969-1976, I hired PA systems from his Hammer Sound company when my own gear was giving problems.
Its 34 years since I left the Wirral, but in that time he, along with David G3UFO, would supply me with snippets of information on microwave activities in the NorthWest to keep my interest whetted.
We eventually caught up again at Friedrichshafen in 2012, and renewed our friendship, with him providing me with details on this very group and BATC to keep me going on the higher bands.
I will miss him, as I miss my old elmer G3UFO, who left us last year, we were all part of the Mersey Microwave group G1GHZ that I founded back in the 80's with their help.
Gone to a higher band :(
Vale Denis
73 Keith VK6KB / VK6EME


Re: Ecoflex 15 Plus at 2,400Mhz

Richard GD8EXI
 


I too was curious how Ecoflex 15+ performed at 2400MHz so as I had 1 metre length made up with these N Type connects at both ends I measure it.

0.58dB loss at 2400MHz with lead nearly straight, raising to 0.74dB with the cable in a circle.

These figures are higher the manufactures figure of 0.16dB per metre but my measurements deliberately included the loss in the two N type plugs.

These figures were actually better than I expected showing it is useable at 2400MHz.

Richard
GD8EXI

On 10/09/2020, 15:36, "Peter LB0K" <lb0k@...> wrote:

Ref your query about Ecoflex15 last year.
The pictures at the website didn’t show any soldering of the centre pin. Was this an accurate assessment??
 

Peter – LB0K
 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Timestep
Sent: 15 March 2019 19:30
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Ecoflex 15 Plus at 2,400Mhz




From:  Dave Cawley
Tel.  01803 833366


Has anyone measured Ecoflex 15 Plus coax at 2,400Mhz ?  I'm using these connectors http://www.kabel-kusch.de/Montagen/UG21-15/UG21-15.htm



Thanks



Dave  G4IUG



Re: mm-wave Contest Sunday 13th September - Activity List

Noel G8GTZ
 

Callsign: G8GTZ/P
Locator: Walbury IO91GI to start with then roving with the aim to have more 122 contacts
Bands: 24, 76, 122,
Talkback: 144.390, ON4KST, Zello, 07881914287
Times: duration of contest


Re: Denis G3UVR SK

Ralph
 

Sorry for the delay.

 

I am very sorry indeed to hear about Denis.  I worked him

A few times with difficulty over an obstructed path but always

Found it worth while. May he rest in peace.

 

73

Ralph G4ALY

 

Sent from Mail for Windows 10

 


Re: Denis G3UVR SK

Chris G0WUS
 

Very Sad news indeed.

I will miss our weekly email exchange on radio and life in general he was always a great help to me in so many ways.

A great chap, a huge loss

Chris

G0WUS

On 10/09/2020 13:56, Ron wrote:
Thanks for the news Andy. So sad.

Met him for the first time at Friedrichshafen last year including a trip up the Pfander during which he began my education in microwave equipment and operation.

Was really looking forward to seeing him again

Ron
G6BMY


Re: mm-wave Contest Sunday 13th September - Activity List

Roger Ray
 

Activity for mm contest on Sunday. All with possibility of change.
Priority is higher mm bands.

Callsign: G8CUB/P
Locator: Hackpen IO91CL35 first hour. Coombe Gibbett IO91GI25. plus others
Bands: 24, 47, 76, 122, 134, 241
Talkback: 144.390, ON4KST, Zello
Times: duration of contest

73
Roger
G8CUB

On 6 Sep 2020, at 21:43, John Quarmby via groups.io <g3xdy=btinternet.com@groups.io> wrote:

The main mm-wave contest of the year takes place next Sunday 13th November, from 0900-1700 UTC (1000 - 1800BST).

This covers all bands from 24GHz to 248GHz. Full rules are here:

https://www.microwavers.org/files/2020-mwrules_v6.pdf

8 character locators must be used, rover operation is permitted.

Please advise your operating plans and I will send out a list on Saturday. The usual format please:

Callsign: G3XDY
Locator: JO02OB
Bands: 24GHz 2.5W 48cm dish
Talkback: ON4KST, Zello, 144.390MHz
Times: Various throughout

73

John G3XDY


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus




Re: mm-wave Contest Sunday 13th September - Activity List

G8ACE
 

Callsign:   G8ACE/P
Locator:    IO91JA & JB   Winchester Cheesefoot area and possibly Stockbridge area later
Bands:      24,  47,  76,  122,  134 GHz
Talkback:  144.390
Times:      Throughout

73

John G8ACE


Re: Wanted Tohtsu CX600NC relay

Andy GD1MIP
 

Thanks Richard (and all) for the offers.

Firstly  I got my CX numbers messed up. My 300w 70cm amplifier uses a CX140D on input and a CX600NC on the output. The offending / damaged  relay is the CX140D. The contact arm (armature?) has bent slightly meaning it's contacts now sit in the middle of the NO & NC connections and the plastic adjusting screw has deformed (excess heat or cheap material?) See picture here.... https://drive.google.com/folderview?id=1ogQ-6vTKJvIyQ_lvDlGNF_lzGzMqHC6U

So I need a CX140D or a better alternative. I see that a couple of UK companies stock them so should be ok. 

Andy GD1MIP 


Re: Has anyone got a good condition WR90 / WG16 X-band waveguide load?

 

Please let me know, but round would not be suitable. 

On Thu, 3 Sep 2020 at 13:41, Robin Szemeti - G1YFG <robin@...> wrote:
Let me check, I may have a Grade 1 Sanders ... but I have a feeling it is round flange.

On Thu, 3 Sep 2020 at 13:32, Dr. David Kirkby, Kirkby Microwave Ltd <drkirkby@...> wrote:
I'm looking for a good condition used a WR90 waveguide load (8.2 to 12.4 GHz) with a low reflection coefficient. Something like an HP X910B Has anyone got anything?

There's a few tatty ones on eBay

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=x910b+hp+termination&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=x910b+hp

that look like they have done 10 rounds with Mike Tyson. 😢😢

I don't want it for amateur purposes, so are not after scrounging it for the bare minimum cost. 😂😂😂 

Dr David Kirkby Ph.D C.Eng MIET
Email: drkirkby@... Web: https://www.kirkbymicrowave.co.uk/
Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100)
Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT.














--
Robin Szemeti - G1YFG







--
Dr. David Kirkby,
Kirkby Microwave Ltd,
drkirkby@...
https://www.kirkbymicrowave.co.uk/
Telephone 01621-680100./ +44 1621 680100

Registered in England & Wales, company number 08914892.
Registered office:
Stokes Hall Lodge, Burnham Rd, Althorne, Chelmsford, Essex, CM3 6DT, United Kingdom


Re: EME ?

Robin Szemeti - G1YFG
 

at least for initial tests, you just need to be able to point it visually at the moon. You'll get around 15 minutes of operation before having to adjust it, or at least I did on 70cm. If you point it at the moon whilst close to apogee, there is only a slight variation in elevation over quite a bit of the arc, you can probably get an hour or so of operation on the same elevation just using a standard rotator azimuth.   

Another cheap and cheerful method of adjusting elevation is a actuator jack off a satellite dish, you can get them on eBay for £20 ... normal rotator to go round and round, satellite dish for elevation.

Plenty of people doing EME portable with just a simple tripod mount.


On Thu, 10 Sep 2020 at 19:43, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Now having a decent sig gen I have just tested the LNA for 23 I have, and find its 23db gain, that and the 20db off the Kuhne gives me quite a bit of gain, not sure of NF on LNA though. 

I thought of using my big helix and the LNA and trvrt to see if I can hear the moon. 
I need to be able to move the antenna in both diretions, left-right, up-down. 
I thought of my telescope, it has a weighted bar so as to offset the weight of the scope so I need to add a shaft with weight to the antenna then get some form of swivel, to get the up-down motion. 

I have found one on ebay, more like a scaffold clamp so not sure how smooth it will be. 

Wonder what others are using?


So, listening out for ON0EME soon, hi. 


Ben



--
Robin Szemeti - G1YFG


EME ?

militaryoperator
 

Now having a decent sig gen I have just tested the LNA for 23 I have, and find its 23db gain, that and the 20db off the Kuhne gives me quite a bit of gain, not sure of NF on LNA though. 

I thought of using my big helix and the LNA and trvrt to see if I can hear the moon. 
I need to be able to move the antenna in both diretions, left-right, up-down. 
I thought of my telescope, it has a weighted bar so as to offset the weight of the scope so I need to add a shaft with weight to the antenna then get some form of swivel, to get the up-down motion. 

I have found one on ebay, more like a scaffold clamp so not sure how smooth it will be. 

Wonder what others are using?


So, listening out for ON0EME soon, hi. 


Ben



Re: Denis G3UVR SK

David Law
 

Very sad news indeed. I have recent fond memories of working Denis on 10Ghz, indoor system to indoor system!
Always enthusiastic, he will be missed by all.
RIP om.


Re: Ecoflex 15 Plus at 2,400Mhz

Dave Cawley G4IUG
 


 
 
If you read the thread the method of test was fully described.  Wimo tested it when returned and agreed with me.
 
Dave


Re: Denis G3UVR SK

G4LDR
 

So sorry to hear that Denis has become a SK. Worked him many times over a difficult path usually at very low signal strengths. I am sure he will be missed by us all.

Neil G4LDR


Re: Ecoflex 15 Plus at 2,400Mhz

Peter LB0K
 

Ref your query about Ecoflex15 last year.

The pictures at the website didn’t show any soldering of the centre pin. Was this an accurate assessment??

 

Peter – LB0K

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Timestep
Sent: 15 March 2019 19:30
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Ecoflex 15 Plus at 2,400Mhz

 

 

From:  Dave Cawley
Tel.  01803 833366


Has anyone measured Ecoflex 15 Plus coax at 2,400Mhz ?  I'm using these connectors http://www.kabel-kusch.de/Montagen/UG21-15/UG21-15.htm

 

Thanks

 

Dave  G4IUG


Kenwood thf7e for sale,cheap

John Worsnop
 

Dual band 144/432 5W FM handheld GWO with wideband rx including 23cm FM rx and SSB /CW Rx  to 144. (Google for details) with antenna and original charger.
£100 + DHL to UK at cost  or collect from Waterbeach. Qthr
73
John G4BAO


Re: Denis G3UVR SK

Clive Elliott GW4MBS
 

So sorry to hear this news. I had been concerned because of his absence from the UKACs on the various bands & his undoubted enthusiasm that there must be something going wrong.

I've only known Denis for the last few years but he was very helpful in encouraging & updating me in the ways of VHF/UHF operating that had taken place in my 33-year QRT period. This help was by email & on air, always on the lookout for me from down here. I was particularly pleased to have worked Denis many times on 23cm mainly CW, often with better reliability than the other bands. He was excited with the prospect of having a go with me on 3cm, but sadly we never got to try that.
--
Clive GW4MBS (ex-G8ADP)
Pottering on 6m - 3cm in a valley in IO71XW where any QSO is a triumph of optimism over geography!


Re: Wanted Tohtsu CX600NC relay

Richard GD8EXI
 


After reading the comment re different versions of CX600N relays I thought I better retest mine, which is about 30 years old and silver-plated inside and out.
 
Isolation
53dB at 30MHz
49dB at 50MHz
39dB at 144MHz
30dB at 432MHz
21dB at 1296MHz
Measured as per the Tohtsu spec sheet with a 50ohm load on the com port.

These figures are ~ 9dB worse than the current manufactures specs adding weight to the idea there are two versions. The nearly flat contacts on mine are only 1.4mm apart and 5.7mm in diameter so a calculated capacitance of 0.65pf so the poor isolation is no surprise.
 
The danger level for some preamps is about 0dBm, 1mW so there is not adequate isolation on VHF, even for a 10 watt Tx without a second isolation relay!
No surprise I destroyed a few GASFETs on 432 MHz!
 
I also tested the isolation of two CZX3500, one dated, 2016, the other brought in about 2009, date now rubbed off.
 
Both >85dB at 432MHz and >80dB at 1296MHz .
 
So plenty of isolation even for a QRO station on 1296MHz
 
The trouble with a second isolation relay is that it will increase your path loss on RX, which could be critical on 432MHz and above for EME and even extreme terrestrial. Certainly not needed with a CZX3500, which is a double relay anyway.
 
As to power handling of the CZX3500s, no I have not destruction tested them yet! However I have used them on both 432MHz and 1296MHz for 400 watts SSB and they survived for years. However with 500 watts of CW on 432MHz the CZX3500 runs hot, so as Alwyn stated not suitable for EME with a 100% duty cycle.
 
 
Richard
GD8EXI


On 09/09/2020, 14:47, "Ian White" <gm3sek@...> wrote:

  

By having the common port pointing the opposite way from the other two, the CX520D saves a lot of space inside a preamp box. I wish there was a wider choice of relays with that connector layout, and at a similar price point (which rules out the big, expensive EME relays) but I have never found even one alternative.
 


However, the problems with poor isolation and poor power handling are surprising. I used the same CX520D in the 70cm EME preamp for many years, handling 1kW CW and connected directly to the GaAsFET preamp, all with no damage. So does the performance really fall over a cliff between 432MHz and 1296MHz?
 


A possible explanation for poor isolation is that there have been at least two versions of that relay, sold under the same model number. In the modern ones, the isolated contacts are grounded onto gold-plated contacts that are screwed into the body. The older ones relied on grounding onto the body itself, which is a poorer contact and also less reliable... bearing in mind that the relay will be operated tens or hundreds of thousands of times, but preamp only has to be unlucky once.
 
 

Yet another thought is about the settings of the moving arms and the actuator plungers. These settings are quite critical to achieve the correct contact pressures, and the TohTsu relays aren't exactly built like Swiss watches.
 


As I said, I do wish there were other relays with that highly practical port layout and at a similar price point.
 

 

73 from Ian GM3SEK

 
 


 

 
 


 

 
 

On 09/09/2020 13:29, Colin Ranson wrote:

 
    
 

Andy,    I think the CX3500 is a copy of the venerable Amphenol 316-10744 series, of which I was fortunate enough to rescue several from a defunct H.O. RF switching station many years ago.   One was 48v, the rest were 26v except one which was 12v !    These are just as good, if not better than the Tohtsu, in build quality at least.

 

What is rare, and I would love one for an application, is the same build but the common (centre) N connector coming out at 180 degrees so that the common can poke out of a plastic (mast head pre-amp) box for connection to the antenna.   Unfortunately the Tohtsu CX520 just does not cut it as far as isolation or power handling is concerned. I burnt one out with 23cm at 240w even when properly sequenced.

 

Regards Colin de G8LBS.

 

Sent from  Mail <https://go.microsoft.com/fwlink/?LinkId=550986>  for Windows 10

 

 

From: Richard GD8EXI <mailto:perwick@...>
 Sent: 08 September 2020 23:05
 To: UKMicrowaves@groups.io
 Subject: Re: [UKMicrowaves] Wanted Tohtsu CX600NC relay

 
 

Andy
     I have one which was retired from active service many years ago as the isolation was not good enough on 432MHz and above, destroying the preamp device. I might sell it but, what band is it for and how much isolation do you need. I can re measure it but from memory it was less than 40dB of isolation on 432 MHz and above, not enough if you are running 100watts plus.
 
 A CX3500 is much better, if you need good isolation, as it has a double switch and the unused bar is grounded both ends. The isolation is so good it is difficult to measure, being in my experience greater than they 65dB they claim, more like 80dB even on 1296MHz.
 
 Richard
 GD8EXI
 
 
 On 08/09/2020, 21:20, "Andy GD1MIP" <gd1mip@...> wrote:
 

Hi, I need a Tohtsu CX600NC 12v DC relay.
 
 Before I buy new from a store does anyone have a spare they'd like to sell?
 
 Thanks Andy GD1MIP
 

 

 

 
 


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