Microwave relay sites for the USAF in the early 1960s...

698;160077 wrote:

Thanks for all the information it is really interesting.
I have been casually researching the link into and out of RAF Wethersfield, which took over from High Garret once the latter closed.
It seems it linked to Barkway to the West and Gt Bromley to the East.
Does anyone know how the link was made from Barkway/Gt Bromley once Wethersfield was vacated by the USAF?
It's seems the microwave system survived for a few more years after the closure of Wethersfield.

There were(are still) two large masts at Wethersfield one very similar to those at other locaions on the microwave link that had the familiar "periscope" antennas, the other was a somewhat smaller mast and located reasonably close the the big mast.
Can anyone give information as to its purpose?

The connection between Wethersfield and High Garret was provided by others prior to the main USAF contract being installed. From memory some voice/data channels were connected at the baseband level.

High Garret must have closed after my time and maybe its equipment relocated to Wethersfield. This would certainly have worked after aerial reflector re-alignments. I cannot suggest what happened after Wethersfield closed because line-of sight between Barkway and Great Bromley would have almost certainly exceeded the specs. There would have to have been a solution because that link was crucial to keep High Wycombe in touch with Europe.

Are you able to tell when High Garret and Wethersfield closed?

DavidS;160083 wrote:

The connection between Wethersfield and High Garret was provided by others prior to the main USAF contract being installed. From memory some voice/data channels were connected at the baseband level.

High Garret must have closed after my time and maybe its equipment relocated to Wethersfield. This would certainly have worked after aerial reflector re-alignments. I cannot suggest what happened after Wethersfield closed because line-of sight between Barkway and Great Bromley would have almost certainly exceeded the specs. There would have to have been a solution because that link was crucial to keep High Wycombe in touch with Europe.

Are you able to tell when High Garret and Wethersfield closed?

Thanks. This is most interesting.
Wethersfield was eventually vacated in October 1990. After closure the previous June a small USAF detatchment remained and I assume it was to maintain the microwave link.
I remember the antennas remained on the mast throughout that summer.

As for the closure of High Garret I don't know date.
I have been told it was in the very late 1960's.

I lifted this photo from Facebook. Cropped, it shows the top of what i believe is the bigger mast at Wethersfiled. The photo was said to have been taken in the 1980's.

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There is one dish pointing, roughly, Eastward and the periscope dish on the west side of the tower angles down.
Was the latter reflecting signals downwards to a ground mounted antenna?

I recall there were also dishes at the top of the mast.

This is how the masts look today.

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The larger mast stands next to the wartime ops room by the looks of it.

The cropped photo is interesting and my guess is that the microwave system we (Marconi) put in was in the process of being upgraded to the new digital backbone i.e. in the 1980s. The eastern dish probably carries the new system and the western reflector is still running the original system.

The periscope system as you call it (I like that name!) consists of two parts: a) a ground mounted dish pointing upwards to b) an angled reflector. The same configuration was used for both transmitting and receiving functions and you can see the two waveguides and horns on the picture below.

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This configuration has a number of advantages:

1. The passive reflector at the top of the mast, once aligned and secured, needs no further maintenance. No climbing and less chance of accidents.
2. The ground-mounted dish can easily be accessed and adjusted even in the most inclement weather. You will notice the dish is not a complete circle thus allowing rain to fall away. If I remember rightly we were able to add heaters to dishes which were very exposed to snow and low temperatures.

It would be good to find someone who was familiar with the system we put in after we did the big contract handover in early 1963 and leading up to the digital backbone upgrade.

DavidS;160006 wrote:

The attached document gives a brief description of the equipment Marconi provided to the USAF.

HM500-550 and HM510-560 Series.pdf

I forgot to add this which was used at each Terminal site.

HM50 Series.pdf

I was posted to the UK 71-74 and 77-79. I worked on the Marconi radios at Daventry, Chelveston and Croughton. I have the Croughton station manual and have scanned a few pages.

Attached files croughton.pdf (633 KB) 

DavidS;160122 wrote:

I forgot to add this which was used at each Terminal site.

HM50 Series.pdf

I've just " Re found" this thread!
Thanks for posting this document (and to others that have posted) I have found them really interesting.

I've lifted this photo off of the RAF Wethersfield facebook page(so credits to them). It still stands there today although it may possibly be "at risk".

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There are other shots of the exterior and interior on the facebook page.
It really looks like it could go back into service at a moments notice.

I understand that there is also one still standing at Gt Bromley condition unknown.

DavidS;160093 wrote:

The cropped photo is interesting and my guess is that the microwave system we (Marconi) put in was in the process of being upgraded to the new digital backbone i.e. in the 1980s. The eastern dish probably carries the new system and the western reflector is still running the original system.

The periscope system as you call it (I like that name!) consists of two parts: a) a ground mounted dish pointing upwards to b) an angled reflector. The same configuration was used for both transmitting and receiving functions and you can see the two waveguides and horns on the picture below.

This image is hidden for guests.
Please log in or register to see it.

This configuration has a number of advantages:

1. The passive reflector at the top of the mast, once aligned and secured, needs no further maintenance. No climbing and less chance of accidents.
2. The ground-mounted dish can easily be accessed and adjusted even in the most inclement weather. You will notice the dish is not a complete circle thus allowing rain to fall away. If I remember rightly we were able to add heaters to dishes which were very exposed to snow and low temperatures.

It would be good to find someone who was familiar with the system we put in after we did the big contract handover in early 1963 and leading up to the digital backbone upgrade.

I can't remember where I got the name 'periscope' from but it is a term I've always used.
I'll try to look back at old photos from airshows the 80's and see if any from the USAF bases that I went to have masts in the background and see if they have similar dishes.

I am assuming that people are familiar with this website?
highgarrett.homestead.com/open.html

There are a few photos of the High Garret masts on there.

The small photo (Wethersfield) shows a "flyswatter" or "board" aerial facing east towards t he next USAF relay station at Great Bromley. It would have reflected out a transmitted beam sent up from a dish aerial on the ground right below. The dish facing west would be the receiver aerial for transmissions from the USAF relay site at Barkway. Also (out of shot) there must have been a corresponding transmitter board for Barkway and receiver dish from Bromley.
I don't know whether DEB ever actually became operational at Barkway, Wethersfield and Bromley--in 1988 it was still a US Congress budget proposal and those 3 relay stations all went off air by 1992.

There's confusion on some websites between Wethersfield shutting as an active airfield and its radio mast shutting down. After its aircraft left Wethersfield stayed on for some years as a reserve field (in case of war), and therefore so would its radio relay mast.

The microwave link at Wethersfield did not close down until 1992. a small contingent of the 2166th staying after the base finally closed in 1990.
There is still a USAF generator trailer parked below the mast at Wethersfield.

I recently found out a photograph of the Dean Hill site that I took during 1964. I remember the station being constructed in 1962/63. We occasionally cycled up there to see what was going on and usually found a US Air Force pick-up truck and sometimes other vehicles present. If I remember correctly there is a WW2 pillbox buried under the mass of brambles in the south-west corner of the site (to the right of the gate) Between the gate and the pillbox was a timber signpost with four arms, each showing the distance in miles respectively to Salisbury, High Wycombe, Madrid and New York. The site is now in private occupation as per the second photo. My pal had only one working brake on his bike and on one visit the cable to that brake snapped while descending Dean Hill and he came to grief against the RNAD boundary fence at the bottom. In fact he almost jumped the fence after running up an earth bank. Happy Days!!.