Date   

Re: Radiall Relay Using Outside Spec

Dave G8KHU
 

Just had a browse on the Radiall website and found this:

https://www.radiall.com/ewscore/download/d/f/bWVkaWEvZG9jdW1lbnRfbGlicmFyeS9UZWNobm9sb2d5X2d1aWRlX1Jldl8yLjAucGRm/

Page 23 discusses hot switching and recommends 1w as a maximum

Sadly there is no information about Colin's relay to supplement Robin's information


Re: Radiall Relay Using Outside Spec

Colin Ranson
 

Thanks Robin !

 

Yo a star !

 

Not suitable for 3.4GHz but not a disappointment .... still very useable .

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Robin Szemeti - G1YFG
Sent: 18 February 2021 15:07
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay Using Outside Spec

 

I use one of those on the output of my 23cm PA, non latching 28V,  2GHz

 

... the spec for them is 400W  or so i am told, I assume that is a "continuous duty" level ... it however has been used with 700W os 23cm SSB for a while now and no issues, although I do have an SMA isolation relay in addition in front of the preamp.

 

 

On Thu, 18 Feb 2021 at 14:57, Colin Ranson <g8lbs@...> wrote:

Afternoon all,

Whilst peoples attention is on here I have a couple of Radial relays, Ref 563703 – wonder if anybody has info please ?  These are transfer with 4 x N sockets, 26v and don’t think they are latching.

 

Regards and thanks

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Robin Szemeti - G1YFG
Sent: 18 February 2021 14:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay Using Outside Spec

 

With good sequencing you would have to be very unlucky to switch it with a TX signal active.

 

 

On Thu, 18 Feb 2021 at 14:35, Dave G8KHU <david@...> wrote:

Hi Mark
and not wishing to teach granny to suck eggs but the 200W spec is the carry power, not the swiching power which from a hazy memory of a chat with Radiall many years ago was sub 1W.

73 Dave


--
Robin Szemeti - G1YFG

 


--
Robin Szemeti - G1YFG

 


Re: Ecoflex 15?

militaryoperator
 

Subject: Re: [UKMicrowaves] Ecoflex 15?

Ben – have a look here: LLA400UF® ULTRA FLEX Coaxial Cable - 1M INCREMENTS (ccsukltd.co.uk) It’s an ultra-flexible version of their own-branded clone of LMR400 and they sell in 1m increments. They also do custom cables Amateur (HAM) Radio Products (ccsukltd.co.uk).
Clive G3GJA


Thanks for info Clive. 

I guess for my 10ft run I'm probably worrying too much. The other option is to mount the SGLab trvrt and pa in a box just under the antenna, might save half a db or so, hi. 

cheers, Ben. 


Re: A proper RAE again

John E. Beech
 

Drop it to single exam 100 Q's 3 Hrs Maximum.

de John G8SEQ

-------Original Message-------
From: Glyn M0XGT <glyn.thomas512@gmail.com>
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] A proper RAE again
Sent: Feb 18 '21 15:07

The current exam structure looks like this:

Foundation: 26 questions, 1-hour, fee £27.50,
Intermediate: 46 questions, 1.5-hour, fee £32.50,
Full: 58 questions, 2-hour, fee £37.50,
[requirement for practical assessments currently suspended due to
Covid-19]

With the proposal to add:
Direct to Full: 130 questions, 4.5-hour, fee £73.00.

Comparing:
130 = 26 + 46 + 58.
4.5 hours = 1 + 1.5 + 2
£73 (save £24.50 on the total)

It looks equivalent to simply running the content of three exams in a
single session (the same numbers of questions in the same timeframe).
This seems reasonable, but 4.5 hr is possibly too long for a single
sitting.

Why not split it into smaller units with a break in between or taken
on different days? – which raises the question of why not just
introduce coordinated “sequential and adjacent” scheduling of the
Foundation, Intermediate, and Full as an option instead. This would
allow the award of Foundation and/or Intermediate if the criteria for
Full was not completely met, whereas the Direct to Full would "all or
nothing".

Glyn M0XGT


Re: Radiall Relay Using Outside Spec

Robin Szemeti - G1YFG
 

I use one of those on the output of my 23cm PA, non latching 28V,  2GHz

... the spec for them is 400W  or so i am told, I assume that is a "continuous duty" level ... it however has been used with 700W os 23cm SSB for a while now and no issues, although I do have an SMA isolation relay in addition in front of the preamp.

image.png


On Thu, 18 Feb 2021 at 14:57, Colin Ranson <g8lbs@...> wrote:

Afternoon all,

Whilst peoples attention is on here I have a couple of Radial relays, Ref 563703 – wonder if anybody has info please ?  These are transfer with 4 x N sockets, 26v and don’t think they are latching.

 

Regards and thanks

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Robin Szemeti - G1YFG
Sent: 18 February 2021 14:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay Using Outside Spec

 

With good sequencing you would have to be very unlucky to switch it with a TX signal active.

 

 

On Thu, 18 Feb 2021 at 14:35, Dave G8KHU <david@...> wrote:

Hi Mark
and not wishing to teach granny to suck eggs but the 200W spec is the carry power, not the swiching power which from a hazy memory of a chat with Radiall many years ago was sub 1W.

73 Dave


--
Robin Szemeti - G1YFG

 


--
Robin Szemeti - G1YFG


Re: A proper RAE again

Glyn M0XGT
 

The current exam structure looks like this:
 
Foundation: 26 questions, 1-hour, fee £27.50,
Intermediate: 46 questions, 1.5-hour, fee £32.50,
Full: 58 questions, 2-hour, fee £37.50,
[requirement for practical assessments currently suspended due to Covid-19]
 
With the proposal to add:
Direct to Full: 130 questions, 4.5-hour, fee £73.00.
 
Comparing:
130 = 26 + 46 + 58.
4.5 hours = 1 + 1.5 + 2
£73 (save £24.50 on the total)   
 
It looks equivalent to simply running the content of three exams in a single session (the same numbers of questions in the same timeframe). This seems reasonable, but 4.5 hr is possibly too long for a single sitting. 
 
Why not split it into smaller units with a break in between or taken on different days? – which raises the question of why not just introduce coordinated “sequential and adjacent” scheduling of the Foundation, Intermediate, and Full as an option instead. This would allow the award of Foundation and/or Intermediate if the criteria for Full was not completely met, whereas the Direct to Full would "all or nothing". 
 
Glyn M0XGT 
 


Re: Radiall Relay Using Outside Spec

Colin Ranson
 

Afternoon all,

Whilst peoples attention is on here I have a couple of Radial relays, Ref 563703 – wonder if anybody has info please ?  These are transfer with 4 x N sockets, 26v and don’t think they are latching.

 

Regards and thanks

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Robin Szemeti - G1YFG
Sent: 18 February 2021 14:51
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Radiall Relay Using Outside Spec

 

With good sequencing you would have to be very unlucky to switch it with a TX signal active.

 

 

On Thu, 18 Feb 2021 at 14:35, Dave G8KHU <david@...> wrote:

Hi Mark
and not wishing to teach granny to suck eggs but the 200W spec is the carry power, not the swiching power which from a hazy memory of a chat with Radiall many years ago was sub 1W.

73 Dave


--
Robin Szemeti - G1YFG

 


Re: Radiall Relay Using Outside Spec

Robin Szemeti - G1YFG
 

With good sequencing you would have to be very unlucky to switch it with a TX signal active.


On Thu, 18 Feb 2021 at 14:35, Dave G8KHU <david@...> wrote:
Hi Mark
and not wishing to teach granny to suck eggs but the 200W spec is the carry power, not the swiching power which from a hazy memory of a chat with Radiall many years ago was sub 1W.

73 Dave


--
Robin Szemeti - G1YFG


Re: Radiall Relay Using Outside Spec

Dave G8KHU
 

Hi Mark
and not wishing to teach granny to suck eggs but the 200W spec is the carry power, not the swiching power which from a hazy memory of a chat with Radiall many years ago was sub 1W.

73 Dave


Re: Matching LDMOS device

Clive, G3GJA
 

Thank you Greg, Geoff and Robin for your helpful replies.

 

The original device was a BLF6G15L-40BR, internally matched for use between 1450-1550MHz. Rated at 40W RF out it was designed for ultra-linear operation at 2.5W output with ACPR of -45dB. It even has an on-die sense FET that looks as though it was used to stabilize the bias, judging by the PCB tracks.

 

I presume the impedance I’m seeing on theVNA will be substantially modified by the matching for the original device; the substrate is very thin and the tracks wide so I’m guessing it’s very low Z, causing it to be a long way from the 1 ohm Greg suggests that the MRF184 might present at 1.3GHz. I’m not competent to work out the Er of the substrate from the matching of the original device from the track dimensions I can see and the known characteristics of the original device from its datasheet, but somebody with a lot more experience might be able to work it backwards.

 

Geoff, the Z I’m seeing is with the new MRF184 fitted. It doesn’t make much difference if it’s biased of not (Vds 28v, Ids 300mA)

 

The original device is only characterized at its intended frequency as here:

 

Table 9. Typical impedance per section

IDq = 330 mA; main transistor VDS = 28 V

 

F                          ZS                               ZL

(MHz)

1480                     3.2- j6.3                4.6- j4.5

1510                     4.4 -j6.5               4.6 - j4.5

 

I’ll have a look at Puff and Robin’s suggestion, SimSmith. It should be possible to run Puff on a guest VM running 32bit Windows in one of the Windows 10 machines.

 

Clive G3gja

 

 

 

 

 

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of Greg - ZL3IX
Sent: 15 February 2021 19:44
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Matching LDMOS device

 

I'm not a PA specialist, but have designed one or two in the distant past. I believe that you need to use the impedance characteristics under drive at a typical power level, and these are not usually the same as would be the case under small signal conditions, ie when measured with a VNA. Making impedance measurements under drive is not a simple matter, and you may do well to take the manufacturer's data, here https://www.nxp.com/docs/en/data-sheet/MRF184.pdf.  Admittedly it only goes to 1 GHz, so you would need to attempt extrapolation up to 1.3 GHz. Even at 1 GHz the plot looks like around 1 ohm for Zin, which is way different from the 13 ohms you measured on your VNA.



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01482 324936

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Re: Radiall Relay Using Outside Spec

DF6NA Rainer
 

Hi Marc,

the relay has a minimum isolation of 80dB @ 3GHz so it will be very usable at 3,4GHz.
Also the Insertion Loss shpuld be no problem. Try it and you will be satisfied !

73, Rainer


Am 18.02.2021 um 14:03 schrieb Mark - M0WGF:

Hi 

I have a Radiall relay R570343010 which is spec as being frequency for 0 - 3 GHz.  I wonder if I could push it's operating frequency up to 3.4GHz?  Has anyone tried or have an opinion on if it will be ok?

I want to stick 15W through it so very much under its 200W rating.

Mark
M0WGF  


Low Noise Power Supplies

Chris Bartram G4DGU
 

Many thanks for the comments on the power supplies, folks.

I should say that I do have suitable linear supplies, these have served me well, but are really too big for my current set-up, and will probably be consigned to recycling.

I also have a small collection of ex-server and similar power supplies, but most of these produce 24 - 28 or 48V. Nothing there is suitable for powering my now fairly aged HF box. However whether I'll even use the old Icom in anger is a moot point!

Mike: thanks for the tip on the HP PSU's. I've actually spent some of my money on a couple! One will probably be going into a screened box with extra filtering on the input (if necessary) and output.


73

Chris

G4DGU


Re: Radiall Relay Using Outside Spec

Mike Willis
 
Edited

Probably. Measure the isolation and match and determine if it is acceptable. Your NanovnaV2 should be able to do that. 

--
Mike G0MJW


Radiall Relay Using Outside Spec

Mark - M0WGF
 

Hi 

I have a Radiall relay R570343010 which is spec as being frequency for 0 - 3 GHz.  I wonder if I could push it's operating frequency up to 3.4GHz?  Has anyone tried or have an opinion on if it will be ok?

I want to stick 15W through it so very much under its 200W rating.

Mark
M0WGF  


Re: Ecoflex 15?

Clive, G3GJA
 

Ben – have a look here: LLA400UF® ULTRA FLEX Coaxial Cable - 1M INCREMENTS (ccsukltd.co.uk) It’s an ultra-flexible version of their own-branded clone of LMR400 and they sell in 1m increments. They also do custom cables Amateur (HAM) Radio Products (ccsukltd.co.uk).

 

Our local repeater group has 4 x 25m runs of the LLA400 in use and they are on a 4 section telescopic tower. No problems at all. They replaced lengths of W103.

 

New drums of replacement W103 cable were going to be used but we found them have much higher attenuation claimed so LLA400 was ordered. Attenuation was spot on.

 

Better still was that a crackle that had affected the 2m repeater for years disappeared. When the old W103 was inspected we found that the copper foil shield had broken into hundreds of segments 4-6cm long. The poor coverage braid (40%) wasn’t enough to join all of the bits.

 

LLA400 claims 95% braid coverage and has a metalized plastic film foil which shouldn’t crack into segments. I would be extremely wary of using any coax that uses a copper foil for shielding.

 

Clive G3GJA

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of militaryoperator via groups.io
Sent: 17 February 2021 22:16
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Ecoflex 15?

 

I have plenty in my scrap bin after it went high loss from before I found out you should never bend it more than once....

.

Neil G4DBN

 

Ah, you have me worried now Neil. I use a telescopic push-up mast with either the 23, 13, 9 or 3Cm antenna on, occasionally more than one but the 10Ghz is 2Mtr down so any old bit of string is ok. 

 

I have a couple of lengths, about 10ft, for the 23, 13 or 9 feeds so there is some flexing needed though of course, the cable hangs vertically (tied to the mast as I erect it) with just the one bend at the bottom to go into the sets. 

 

Maybe the flexibility of the LMR400 is handy. The loss per 10ft )1500Mhz) would seem to be 0.51db for LMR400, 0.33db for LMR600 and 0.41db for eco15.

 

LMR600 might be a better choice. 

 

Ben.



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HESH Computer Services

hesh.co.uk
01482 324936

8 Louis Pearlman Centre, Goulton Street, Hull, HU3 4DL

Registered in England No. 3003479. The information contained in this email may be legally privileged and/or confidential. If you are not the intended recipient, use of this information (including disclosure, copying or distribution) or any action taken, or omitted to be taken, in reliance on it is prohibited and may be unlawful; therefore please inform the sender and delete the message immediately. The views expressed in this email are those of the originator and not necessarily those held by HESH Computer Services Ltd, who do not accept liability for any action taken in reliance on the contents of this message or for the consequences of any computer viruses which may have been transmitted by this email.


Re: Low Noise Power Supply

Jim Mcilroy
 

Hi

If it doesn't have to be switched mode have a look around for a Kenwood PS-30 which may occasionally be found seconhand from dealers.

These will do 13.8V at 15A continuous and intermittently up to 20A

I have used one for years. They are electrically quiet, and I have also seen them being used to power commercial VHF repeater systems.

73

Jim  G4EQX


On 18/02/2021 11:26, Colin Ranson wrote:

All, Chris Bartram.

 

On the subject of noise from a SMPSU – a long time ago I acquired a Farnell 75amp 28volt unit. Its located in my loft at the moment, and is also remotely turned on and off from the shack (long story as to why)   As an experiment last night I connected about 40ft of wire to the + terminal and ran it round the loft.   I could not detect, or see, any increase in noise on any band (IC-7300) 1.8 – 70MHz.  

 

These PSU’s were obviously made to the enormous price they fetched when new. No doubt proper design and filtering.

 

I also have an Agilent E3648 Lab PSU in the shack, not sure if SM or Linear but full of digital stuff....    no interference from that either.

 

Chris, as I mentioned earlier, don’t buy a Nissei MS-1228 ‘Professional’ SMPSU..... outputs loads of crap on HF/Lo VHF. And personally I would not buy one of these ‘tweakable’ SMPSU’s to move sprogs away from the station you want to work.  Had one of these at a club station.... awful !

 

Best regards

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Brian Howie GM4DIJ
Sent: 18 February 2021 10:30
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Low Noise Power Supply

 

In message <9b0cfc04-b30d-faba-2395-3d5cba425a26@...>,
Chris Bartram G4DGU <chris@...> writes
>Nothing to do with microwaves, except possibly that it will help me
>sort-out/rationalise my workroom/shack, and thus help hasten my return
>to having an operational station.
>
>Does anyone have any (polite!) suggestions regarding a low-noise 12V
>20A+ switching PSU?
>
>73
>
>Chris G4DGU

I bought a  used HP ProLiant 750W PSU Power Supply   from e-bay last
year to use /P , rather than lugging a heavy linear supply. They come in
at about £12 and easy to mod for 13.8V or you can  leave them at 12V.

Http://www.gm0onx.co.uk/  under low cost SMPU

HP ProLiant DL360 G6 750W Power Supply (HSTNS-PD18 version)

They seem quite enough for what I do.

There's plenty of suppliers.

Brian GM4DIJ
--
Brian Howie




 


Re: Low Noise Power Supply

Colin Ranson
 

All, Chris Bartram.

 

On the subject of noise from a SMPSU – a long time ago I acquired a Farnell 75amp 28volt unit. Its located in my loft at the moment, and is also remotely turned on and off from the shack (long story as to why)   As an experiment last night I connected about 40ft of wire to the + terminal and ran it round the loft.   I could not detect, or see, any increase in noise on any band (IC-7300) 1.8 – 70MHz.  

 

These PSU’s were obviously made to the enormous price they fetched when new. No doubt proper design and filtering.

 

I also have an Agilent E3648 Lab PSU in the shack, not sure if SM or Linear but full of digital stuff....    no interference from that either.

 

Chris, as I mentioned earlier, don’t buy a Nissei MS-1228 ‘Professional’ SMPSU..... outputs loads of crap on HF/Lo VHF. And personally I would not buy one of these ‘tweakable’ SMPSU’s to move sprogs away from the station you want to work.  Had one of these at a club station.... awful !

 

Best regards

 

Colin de G8LBS.

 

Sent from Mail for Windows 10

 

From: Brian Howie GM4DIJ
Sent: 18 February 2021 10:30
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] Low Noise Power Supply

 

In message <9b0cfc04-b30d-faba-2395-3d5cba425a26@...>,
Chris Bartram G4DGU <chris@...> writes
>Nothing to do with microwaves, except possibly that it will help me
>sort-out/rationalise my workroom/shack, and thus help hasten my return
>to having an operational station.
>
>Does anyone have any (polite!) suggestions regarding a low-noise 12V
>20A+ switching PSU?
>
>73
>
>Chris G4DGU

I bought a  used HP ProLiant 750W PSU Power Supply   from e-bay last
year to use /P , rather than lugging a heavy linear supply. They come in
at about £12 and easy to mod for 13.8V or you can  leave them at 12V.

Http://www.gm0onx.co.uk/  under low cost SMPU

HP ProLiant DL360 G6 750W Power Supply (HSTNS-PD18 version)

They seem quite enough for what I do.

There's plenty of suppliers.

Brian GM4DIJ
--
Brian Howie




 


Re: Ecoflex 15?

John Fell
 

For > 432MHz I have used Andrew Heliax 1/2" Superflexible ,foam dielectric cable for turning loops and LDF450 A for straight runs .

LDF450 will survive without loss increase upto the point where the outer solid copper shield starts to crack - this material is substantial and NOT any kind of thin film construction.

Amateur uses tend to put cables into areas that are not specified as suitable by the original manufacturers .This includes contesting - I used to operate with G4RFR and our various reels of 450 were stored in 5Ft rolls , used approximately 8 times a year over a 15 year period .Failure was low and by far the largest failure seen was due to miss handling during setup,strip down .In some cases it survived where a bend had caused the outer shield to flatten and was reformed (not good practice ! ).

People get put off using it , I think , because it is stiffer than UR67 and terminations are "expensive" .

This issue can be solved by using a bored out backnot and turning up a small brass impeadance transformer for the inner solid copper (or plated Alum) conductor .
Design in most UK Microwave Amateur books .I have on occasion formed one using a 1/2" pillar drill and a flat hand file .
The assemblies can be fully soldered and if this is taken through the Hex backnut will stop suck outs to well above 10GHz .

It is not good value to spend a long time building low noise kit and deploying shonky cables that act as resistive pads or actual noise sources .

At least the current crop of handheld VNAs can tell you where it's all gone Pete Tong 

This topic will be repeated ad nauseum ......

73
John
G0API 


On Thu, 18 Feb 2021 at 00:01, Robin Szemeti - G1YFG <robin@...> wrote:
I tend to use flexible heliax, FSJ4-50B is my tool of choice.

On Wed, 17 Feb 2021 at 23:04, Neil Smith G4DBN <neil@...> wrote:
I have a 25 m run of Ecoflex 15 plus that has never been moved and it is
as good now as when it was installed.  However, the runs that I had on
the pump-up, which were coiled carefully into a 1m diameter heap and
raised/lowered once a day on average, started to get suck-outs and
lossiness at 23cm and 13cm after six months. Might have happened sooner,
but I noticed things were getting slightly worse over time. Same with
some patch leads that Tony brought round.  Some that were 2m long had
3dB loss at 13cm and 1.5dB at 23cm, and the loss changed as you moved
the cables. After slicing off the insulation, we found that the copper
foil was split into sections a couple of inches long, with only the
scanty outer braid carrying the current between the sections. It is a
bit of a swine to terminate reliably as well. Flexy heliax is hugely
more practical.

Neil G4DBN








--
Robin Szemeti - G1YFG


Re: Ecoflex 15?

david656179
 

My experiences and opinions, may or may not not be typical. DYOR.

M&B Hyperflex 10  has more cores in centre, so far rotator loop no problems, M&B Ultraflex 10 seems equally good.  Ultraflex 13 also has big number of centre cores and the more recent batches I have bought meet published specifications,  There were early batches that seemed not to meet spec (or perhaps spec  improved latterly) in all cases though, despite some rough treatment at times on temporary set ups, examination of lengths cut have showed no foil  radial cracking that can happen on Ecoflex and W103.  Of course W103 is not designed for flexing, for permanent installations, it is a very good choice for low loss runs up to and including 23 cm, just never flex or roll up.

Currently 20 m of M&B Ultraflex 13 in use on 23 cm, just one length. including around rotator on scam 12 pump up, much abused with the ups and downs and getting caught on the shrubs/ mast legs.  So far unable to detect spec changes, when checking with the power in/out method.  The Ultraflex connectors are solderless for 13 and some on 10 as well.  The connectors (provided you pay a proper price that is, some poor copies out there), are excellent quality.  The M&B PL259 plugs for Ultraflex 10 are quite excellent, by far the best connector I have used, all of the M&B connectors make excellent and permanent connections to the screen/braid and are highly water resistant.

A short length of RG213, especially the double screened versions, will still be the best "fit and forget" option for a rotator loop, especially if your masts have to be professionally rigged, removes any anxiety about foil cracking failure.

I remember the Camb Hams group repeatedly reporting problems with Ecopflex range on their portable activities, they changed to something else but I forget what it was, with no further problems IIRR.


Re: Low Noise Power Supply

Brian Howie GM4DIJ
 

In message <9b0cfc04-b30d-faba-2395-3d5cba425a26@chris-bartram.co.uk>, Chris Bartram G4DGU <chris@chris-bartram.co.uk> writes
Nothing to do with microwaves, except possibly that it will help me sort-out/rationalise my workroom/shack, and thus help hasten my return to having an operational station.

Does anyone have any (polite!) suggestions regarding a low-noise 12V 20A+ switching PSU?

73

Chris G4DGU
I bought a used HP ProLiant 750W PSU Power Supply from e-bay last year to use /P , rather than lugging a heavy linear supply. They come in at about £12 and easy to mod for 13.8V or you can leave them at 12V.

Http://www.gm0onx.co.uk/ under low cost SMPU

HP ProLiant DL360 G6 750W Power Supply (HSTNS-PD18 version)

They seem quite enough for what I do.

There's plenty of suppliers.

Brian GM4DIJ
--
Brian Howie

2981 - 3000 of 64106